1. 1Thursday, 3rd June, 1999

    2 (Open session)

    3 (The accused entered court)

    4 (The witness entered court)

    5 --- Upon commencing at 9.00 a.m.

    6 THE REGISTRAR: Case IT-95-16-T, the

    7 Prosecutor versus Zoran Kupreskic, Mirjan Kupreskic,

    8 Vlatko Kupreskic, Drago Josipovic, Dragan Papic, and

    9 Vladimir Santic.

    10 JUDGE CASSESE: Thank you. Good morning.

    11 Good morning, Professor Wagenaar. I would

    12 like to ask you to make the solemn declaration,

    13 please.

    14 THE WITNESS: I solemnly declare that I will

    15 speak the truth, the whole truth, and nothing but the

    16 truth.

    17 JUDGE CASSESE: Thank you so much. You may

    18 be seated.

    19 Counsel Par?

    20 MR. PAR: Good morning, Your Honours.


    22 Examined by Mr. Par:

    23 Q. Good morning, Professor Wagenaar. Do you

    24 hear me well, Professor?

    25 To begin with, Professor, I should like to

  2. 1ask you, for the record, to give us your full name,

    2 please.

    3 A. My name is Willem Albert Wagenaar.

    4 Q. Thank you. Would you be kind enough to

    5 convey to the Court some information about your

    6 professional career, the posts you have held in the

    7 past and that you are holding at present?

    8 A. I am an experimental psychologist, and

    9 experimental psychology deals with the general

    10 psychological faculties that humans have, like

    11 perception, visual perception, auditory perception,

    12 memory, and general capabilities like that.

    13 I was first trained at Utrecht University and

    14 defended my dissertation at Leiden University. From

    15 there on, I worked for 20 years in the Institute for

    16 Perception, TNO, which is a separate research institute

    17 in the Netherlands that deals with mostly questions of

    18 perception, and face perception is one of the topics

    19 that I addressed there.

    20 From 1974 till 1985, I held the post of head

    21 of the psychology department in that institute. In

    22 1983, I was appointed as a partial professor at the

    23 University of Leiden, and in 1985 I moved completely to

    24 the University of Leiden, where I held the post of

    25 experimental psychology.

  3. 1From 1987 till 1989, I was dean of the

    2 faculty of social sciences, and, now, from 1997 till

    3 today, I am the vice-chancellor -- or, as we say, the

    4 rector magnificus, of Leiden University.

    5 Q. Thank you. Please, Professor, could you now

    6 tell us briefly something about your scientific work,

    7 the papers you have published in your field and some of

    8 the studies you have done in the area of human

    9 perception.

    10 A. Yes. By now I have published more than 150

    11 publications. Many of them deal with problems of

    12 perception and problems of memory, in which the

    13 question usually is the problem of remembering what you

    14 saw. Many of these publications are in the context, or

    15 immediately inspired, even, by problems that occur in

    16 the judicial process, like processes of, say, what

    17 witnesses can see, what witnesses can or do remember,

    18 what the reliability of eyewitness testimony is. I

    19 have published several books on this problem, again,

    20 usually inspired by very concrete trials in which such

    21 questions were asked to me. I have acted as an expert

    22 witness on such questions in, I estimate, more than 200

    23 trials.

    24 Q. Among other things, you have also testified

    25 in this International Tribunal, I believe?

  4. 1A. Yes, I have testified in the Tadic case,

    2 which I think was one of the first trials that took

    3 place in this Court.

    4 Q. Thank you, Professor. Now that we have

    5 learned, at least in broad lines, something about your

    6 professional activities and scientific work, can we go

    7 on to your expert opinion provided for the needs of

    8 this trial. To facilitate your presentation, I should

    9 like to provide Their Honours and the parties a copy of

    10 your expert opinion.

    11 MR. PAR: I should like to ask the usher for

    12 his assistance to help me distribute these documents.

    13 THE REGISTRAR: This is Exhibit D58/3.

    14 MR. PAR:

    15 Q. Professor, upon the request of the Defence of

    16 the accused, Vlatko Kupreskic, you have provided your

    17 expert opinion on the identification of Vlatko

    18 Kupreskic by Witness Q. Could you please tell us what

    19 kind of information and data that you obtained from the

    20 Defence, you used when providing your expert opinion?

    21 A. Yes, I received, from the Defence, an

    22 introducing letter explaining what the problem was they

    23 wanted me to address, and as I have here a partial copy

    24 of the trial record that represents -- which is the

    25 most important for me -- some statements by the

  5. 1Witness Q and some other witnesses.

    2 Q. Thank you. To have a more complete idea as

    3 to the kind of letter that you used, I should again ask

    4 the usher to help me provide Their Honours and the

    5 Office of the Prosecutor with a copy of that letter.

    6 Talking about this letter, Professor, you

    7 said that it contained a certain number of data which

    8 you used when drawing up your expert opinion. I would

    9 suggest that I read out that part from the letter

    10 containing that information, the initial situation that

    11 we described in that letter in which the recognition

    12 took place. As Their Honours have a copy of that

    13 letter, and the Prosecutor, let me just read the part

    14 that is relevant.

    15 THE REGISTRAR: This is Exhibit D59/3.

    16 THE INTERPRETER: Could a copy be placed on

    17 the ELMO, please?

    18 MR. PAR:

    19 Q. The letter describes how the Defence

    20 presented the situation under which recognition was

    21 carried out, and so I'm reading from the letter. The

    22 event and the conditions under which recognition took

    23 place, according to the statements of the witness whose

    24 testimony we are interested in, were the following:

    25 "During the military activities in a Bosnian village

  6. 1on the 16th of April, 1993, around 9 a.m., a group

    2 consisting of several civilians -- women, children, and

    3 elderly people -- fled from their homes in order to

    4 save their lives. Shooting from light and heavy

    5 weapons was in course for several hours. Murders and

    6 burning of houses were ongoing, and the group decided

    7 to save themselves by escape. The group was moving

    8 along a sheltered part of the terrain. Then they

    9 climbed a small hill, and, at that point, they came out

    10 on terrain where they were spotted by enemy soldiers.

    11 The group at that point was faced away from the

    12 soldiers. They had their backs turned on the soldiers,

    13 and in one moment they heard loud swearing and threats

    14 coming from the soldiers. The group turned around for

    15 a moment. They looked at the soldiers, who were

    16 standing approximately 60 metres away from them, and in

    17 that moment, the soldiers started to shoot at the

    18 group. On that occasion, one person was killed and two

    19 persons wounded."

    20 That is the part of the letter which we sent

    21 to you, and in which we, as the Defence, described the

    22 situation as we assumed it was.

    23 In continuation of this letter or, rather,

    24 our request for your expert opinion, we have asked

    25 eight specific questions. That is, we asked you to

  7. 1give us your expert opinion regarding eight factors

    2 which could have affected the reliability of the

    3 identification.

    4 In your written opinion, you responded to

    5 each of these points, so I should like to ask you to

    6 present those answers yourself, directly, in this

    7 courtroom. Would you please begin your presentation

    8 with the first part of your finding, where you noted

    9 that there were two different modes of identification,

    10 person identification, and could you describe briefly

    11 both modes and then tell us which were the points that

    12 we set and what your expert opinion about them is.

    13 A. Generally, there are two situations in which

    14 a problem of person identification may occur. One is

    15 the situation in which a witness recognises a person

    16 known to him or her already before the time of the

    17 crime. So that's the problem of identifying,

    18 recognising, a well-known person. That process can be

    19 very fast. In a flash, you may recognise someone whom

    20 you have known all your life, for instance. Later on,

    21 the only thing you have to remember is the fact that

    22 you recognised that person. You don't have to

    23 remember, say, the whole image of that event. It is

    24 sufficient, for instance, to recall, to remember, the

    25 name of the person you have recognised. That's

  8. 1situation 1.

    2 Situation 2 is when, during a crime, you are

    3 faced with a person you have never seen before, so you

    4 can't try to remember the name of that person because

    5 you don't know that person. Then, usually later on,

    6 for instance, in an identity test, you are again

    7 confronted with that person or a number of persons in a

    8 line-up, and the question is whether you recognise that

    9 person. In order to do that, it is necessary that you

    10 have stored, from the time of the crime on, an image of

    11 the person you saw, because in your head you have to

    12 compare the image that you saw originally with the

    13 image of the person you see now.

    14 Now, these two processes are entirely

    15 different, and the factors that influence the one are

    16 not necessarily the same as the factors that influence

    17 the other.

    18 Now, in the case we are discussing today, we

    19 are dealing with situation 1. The task was to

    20 recognise a person that was supposedly known to the

    21 witness long before. So the factors that are relevant

    22 in this case are the factors that influence the

    23 immediate recognition process. The problem of recall,

    24 of remembering, is minute, is very small, because the

    25 only thing that had to be remembered, in fact, is the

  9. 1name of the person who was seen there at the scene of

    2 the crime. So factors that influence remembering or

    3 forgetting are probably not very relevant because the

    4 task to the witness was only to remember the name of

    5 the person he saw. So decisive factors are factors

    6 that influence perception, recognition on the spot, and

    7 not factors that deteriorate your memory, because the

    8 memory task is very slight.

    9 Now, in the list of eight questions that you

    10 gave me, some of the questions are in fact addressing

    11 the perception situation and are therefore highly

    12 relevant, and some address the problem of remembering

    13 and are therefore probably not so relevant. So that's

    14 the distinction that I made.

    15 Now, in my letter to you, I started to

    16 explain that in my opinion, the most relevant factor

    17 is, in this case, the observation distance, which was

    18 presented to me as being in the order of 60 metres.

    19 That is a highly-relevant factor, because if you are at

    20 such a distance that you can't see the face of a

    21 person, then everything else stops, then there is

    22 nothing to put into your memory. There's no memory

    23 problem also.

    24 The first question to be addressed is is it

    25 possible to recognise a person known to you, known very

  10. 1well to you, at a distance of 60 metres in such a way

    2 that we can safely say that no mistake is possible.

    3 Now, at this point there is a problem that

    4 can only be solved by the Court, and that is how

    5 reliable should such a recognition be. Some

    6 experimental data that I have provided to you is that

    7 under optimal conditions, to our best knowledge, the

    8 chances that you recognise a familiar person at a

    9 distance of about 60 metres are something like 50

    10 per cent correct, 50 per cent wrong, or worse, that

    11 that would probably be the best performance. So I'm

    12 not saying that you cannot recognise a person at 60

    13 metres, but I am saying that 50 per cent wrong is not

    14 highly reliable in a legal sense. It is quite possible

    15 that the person would make a mistake. In my opinion,

    16 it would be at least as likely that the person makes a

    17 mistake as that the person would be correct.

    18 Now, whether that level of reliability is

    19 good enough for the Court, I cannot decide. I can only

    20 give the information.

    21 Now, if I want to go into some detail, I

    22 would like to explain that we are confronted here with

    23 a biological fact. Our eyes are built to perceive, and

    24 inside the eye, say the area where, say, the light hits

    25 the receptor is called the retina, and the retina

  11. 1contains a very large number of small receptors called

    2 cones, and the cones are placed in some sort of mosaic

    3 pattern, and it is clear that a detail that is smaller

    4 than a cone cannot be clearly resolved, as we say it,

    5 by the retina. A detail needs to cover at least one

    6 cone, but it would be a lot better if it would cover a

    7 number of cones so that the shape of that detail will

    8 be perceived.

    9 Now, the density of cones, the number of

    10 cones on a square millimetre, is a biological fact and

    11 is almost invariably the same for all people. It's not

    12 the same for all living beings. Eagles have a much

    13 denser placement of cones and they can see a lot more

    14 details. But humans are not eagles. The density of

    15 cones in the human eye is the same for all persons,

    16 with very slight variations.

    17 Another fact is that the details in a human

    18 face that you need to see in order to make sure that

    19 this is the one person, not the other person, are in

    20 the order of half a centimetre. If you can't see

    21 differences of half a centimetre, then you confuse the

    22 one shape of an eye with another shape of an eye, the

    23 one shape of a nose with another shape of a nose. In

    24 order to recognise a person, you need to see details of

    25 about half a centimetre, and if the distance, the

  12. 1observation distance, is so large that half a

    2 centimetre on a face falls just within one cone, then

    3 you cannot resolve these details anymore, you cannot

    4 see them, and it becomes rather tricky to recognise a

    5 person.

    6 These results are confirmed in a number of

    7 studies, and I've done some of these studies myself,

    8 and it is quite obvious that the details that the eye

    9 can see at a distance of 60 metres are in the order of

    10 two centimetres, not smaller, and definitely not half a

    11 centimetre, and that's why, at a distance of 60 metres,

    12 it becomes rather likely that you will make mistakes.

    13 I'm still not saying that you can't recognise a person

    14 at 60 metres, I'm only saying the likelihood of

    15 mistakes become rather high.

    16 Now, what I'm telling you is related to

    17 optimal viewing conditions like perfect daylight, you

    18 have all the time that you want, there is no haze, no

    19 fog, no smoke. All these other factors can make it

    20 more difficult to recognise a person. If there's no

    21 perfect daylight, if there is smoke, if you see the

    22 person for a very short time, all that makes it more

    23 difficult. But even under optimal conditions, the

    24 likelihood of a mistake would be rather high.

    25 Q. Excuse me. If I may interrupt you just for a

  13. 1moment.

    2 Could you please tell us, this percentage of

    3 error, how does it grow with distance?

    4 A. In my letter to you, I gave you a small table

    5 that is based on my own research, and if you take the

    6 last column of that table with the heading "3.000," and

    7 "3.000" refers to the elimination level and "3.000"

    8 represents a normal day, somewhat clouded but normal

    9 daylight, and then the numbers in that table give you

    10 the ratio of correct answers to incorrect answers.

    11 So, for instance, in the second row, if it

    12 says "108," then there are 108 correct answers to one

    13 wrong. So these numbers are odds, the odds of making a

    14 correct identification.

    15 Now what you see is that at 3, 5, 7, and 12

    16 metres, the odds of making a correct identification are

    17 rather high; 27, 108, 55, 90. There is always some

    18 variation because these are experimental data, not

    19 theoretical data. And suddenly at 20, it drops to

    20 below 5. That sudden drop represents the moment where

    21 suddenly the details of half a centimetre fall within

    22 the area of one cone in the retina. If they fall over

    23 several cones, there is no problem and distance is not

    24 even so important. But at the critical point somewhere

    25 between 12 and 20 metres, the details become too small,

  14. 1and then the ability to recognise a person suddenly

    2 drops.

    3 I have never done distances longer than 40

    4 metres because, from this table, it's quite clear that

    5 at 40 metres the likelihood of making errors is already

    6 so large that it would be useless to research longer

    7 distances.

    8 Q. That is just what I wanted to ask you, "Why

    9 don't you go further, after 40 metres," so now you have

    10 given us the explanation for this procedure.

    11 I interrupted you, Professor. When you were

    12 talking about other factors influencing perception, you

    13 mentioned the distance, the lighting and other

    14 circumstances. So please continue, and I apologise for

    15 interrupting you.

    16 A. Well, this far I have discussed, in fact,

    17 your question number 3, and I took that first because I

    18 think that observation distance is the most crucial in

    19 this case.

    20 If you now go back to question number 1, the

    21 fact that the witness was in life danger, in our

    22 research, we call this the factor of the presence of

    23 emotions, and what I have explained to you in my letter

    24 is that emotions can have two effects, or generally

    25 it's assumed that emotion has the effect that your

  15. 1field of attention becomes smaller. You focus your

    2 attention upon one thing, the one thing that's most

    3 crucial to you. The fact then of emotion can be that

    4 you perceive that one thing better, and you may also

    5 remember that better. In that sense, emotion can

    6 improve the observation. But if you focus your

    7 attention on a particular thing at the same time,

    8 naturally you don't pay attention to some other things,

    9 and the likelihood that you will perceive those other

    10 things and remember them becomes smaller.

    11 So the effect of emotions mean generally that

    12 you will remember some things better and other things

    13 worse. The only question is where did you fixate, what

    14 was important for you at that time, and it's very hard

    15 to tell because a person under high emotions is not so

    16 rational. What will be selected as the thing to focus

    17 at might not always be what is the most relevant at the

    18 time of a trial.

    19 So it's very hard to say what emotions in

    20 this present case would have done. My science doesn't

    21 give me enough guidance to say whether emotions would

    22 have helped or would have had the opposite effect.

    23 The question number 2 relates to the fact

    24 that the witness looked just for one moment. Well, in

    25 principle, you can recognise a person in one eye

  16. 1fixation, and you can make one eye fixation in half a

    2 second, and I would say one moment probably is at least

    3 half a second. That should be enough for recognising a

    4 person that you know so very well. So that should not

    5 be a problem, in principle.

    6 Question number 3, I answered already.

    7 Question number 4 is the problem that the

    8 person who was recognised, whoever he was, was standing

    9 in a group, so there was more to see than just that one

    10 person. Now, what I reckoned in my letter, that if

    11 this were a closed group of people, standing together,

    12 then, at a distance of 60 metres, you don't need more

    13 than one fixation to see the whole group. If you look

    14 at one point, there's a certain area around that point

    15 that we can see without moving our eyes; we call that

    16 the stationary field. Other things, outside this

    17 stationary field, can only be seen if we move our eyes,

    18 and eye fixations take time. So the larger the group,

    19 the more fixations you need to make and the more time

    20 you need. But if four persons stand closely together,

    21 they can be seen in one eye fixation, and the fact that

    22 there is a whole group doesn't matter so much; they can

    23 be seen all at the same time. So that, in principle,

    24 should not be a problem.

    25 Question number 5 was the age of Witness Q.

  17. 1Now, age-related eyesight problems are usually problems

    2 of reading, problems of seeing at a very short

    3 distance; usually the eyesight for a long distance

    4 remains the same. I say "usually" because of course

    5 there are individual differences. But without further

    6 information about Witness Q, I can only say, if he is a

    7 normal person, at 55 he will have already some reading

    8 problems and probably needs eyeglasses for reading, but

    9 not for a distance. If the opposite is claimed, the

    10 obvious solution, to find an answer to this question,

    11 is to send him to an ophthalmologist and ask him to

    12 study his eyes. I can only tell you what usually would

    13 happen, so I would say that the age of Witness Q with

    14 respect to his eyesight is probably not relevant.

    15 Question Number 6, the fact that other

    16 persons who were also watching the scene couldn't

    17 recognise anyone, well, what I explained in my letter,

    18 I'm not surprised at that, because, in fact, I do not

    19 expect that people would correctly recognise another

    20 person at a distance of 60 metres, so the fact that the

    21 others didn't recognise anyone needs no further

    22 explanation. What we need to explain, how it was

    23 possible that one of them still, at a distance,

    24 recognised someone. So there is no real conflict. Of

    25 course they didn't recognise anyone.

  18. 1Seven -- and here we go into the memory

    2 problem -- the fact that Witness Q could not explain

    3 what kind of clothing the person he saw, and he said he

    4 recognised, was wearing. Well, in order to recognise

    5 him at that time, on the spot, he didn't need to pay

    6 attention to the clothing of that person; the face is,

    7 of course, the most important thing if you want to

    8 recognise anyone. And for remembering who he saw, he

    9 only needed to remember the name of the person. It's

    10 not necessary at all that he also remembered the image

    11 that he saw, so that later on he could tell you, "On

    12 that image of this person, I can now also tell you

    13 which clothes he was wearing."

    14 So, given that the clothes of this person

    15 were probably not relevant to him at all -- usually the

    16 weapon is the most important thing, and then the face,

    17 but the clothing is not relevant -- and the fact that

    18 in order to make his testimony he needed only to

    19 remember the name of that person, it's not surprising

    20 that after some time, when he finally made his

    21 testimony, he didn't remember the clothing. So that's

    22 not a problem.

    23 Question Number 8 is a rather complicated

    24 question, and if I may, I need some time to explain why

    25 that is complicated, because Question 8 is related to

  19. 1what I say, as a general term, called "suggestion." If

    2 we see something that is not very clear and we store

    3 the unclear information in our heads, then it's quite

    4 possible that what we call "post-event information,"

    5 information that reaches us afterwards, will sharpen

    6 that image, will affect that image, and also may change

    7 that image, because the image of what we saw, in our

    8 heads, is not stable at all but is constantly

    9 reprocessed in the context of knowledge that we

    10 receive.

    11 Human memory is not like a video recorder,

    12 where the recording stays unchanged. Human memory is

    13 very active, is very much alive, and information that

    14 we have is not simply stored and recalled when we need

    15 it; no, it's constantly processed in the context of

    16 knowledge that we receive. That's very useful for

    17 people, very useless for a court, because we would

    18 rather like witnesses to be like video recorders, but

    19 unfortunately, they are not.

    20 Now, your question is the fact that later on,

    21 the witness received information about the person he

    22 recognised -- now living in his house, if I am

    23 correct -- may have affected the image that he

    24 remembered, and I can, of course, not describe what

    25 happened; I can only describe what may happen in a

  20. 1person. I must say the most important condition for

    2 post-event-information-induced changes to occur is that

    3 the first observation is not totally clear. If I have

    4 a totally clear initial observation, probably there's

    5 no new information that may change that, but if it's

    6 not clear, if it's vague, then there is an opportunity

    7 for what you may call a sharpening of the image as a

    8 consequence of receiving new information.

    9 Now, what I would say is that seeing a person

    10 at 60 metres creates not a sharp image of a particular

    11 face, because the critical details are not resolved in

    12 the retina. It creates a vague image that may be

    13 recognised correctly, but also maybe is confused with

    14 another person. Now, that vague image is a perfect

    15 basis for post-event information to have an effect, and

    16 I listed in my letter a number of pieces of information

    17 that could have such effect, like the fact they were

    18 standing in front of a certain house, or some facts

    19 that are known about the accused -- that he belongs to

    20 some group, or that he might have had a weapon; all

    21 sorts of information that may come later may influence

    22 that image.

    23 It is very hard to limit the sort of

    24 information that can have that effect, and I'm not

    25 perfectly aware of all the information that has been

  21. 1presented to Witness Q about the accused, so it's very

    2 hard for me to even guess what has happened. I only

    3 can say that the starting position of a vague image,

    4 seen at a distance of 60 metres, is a good starting

    5 point for suggestive post-event information to have

    6 effect.

    7 Now, an important aspect here is that if you

    8 have a very clear image, you can also say immediately

    9 whom you have recognised. Recognition is usually a

    10 process that happens very quickly. You see something.

    11 You say, "I know who that is." Recognition is not

    12 something that is spread out over a month, so that

    13 first, you didn't know it; after several months, you

    14 know it. That process, very gradually, you start to

    15 realise what or whom you saw, is totally different from

    16 immediate perception. It is a construction. When you

    17 start to realise, you use all sorts of information to

    18 make the vague image that you have in your head

    19 sharper, and at the end, you know -- "Ah, but now I

    20 know what that vague image in fact means." But that's

    21 not perception; that is reconstruction, and

    22 reconstruction is very much influenced by information

    23 that you receive during that period.

    24 So the two important elements here, although

    25 I cannot answer your question whether suggestion has

  22. 1occurred, but the two important elements are the

    2 initial position is good for suggestion, because it's a

    3 vague image, and as far as I could tell from the

    4 information that I received, recognition was not

    5 immediate. It was a process that took a while, and

    6 only after a certain amount of time, Witness Q

    7 testified that he knew who that was.

    8 Q. I have a question with regard to that. I'm

    9 interested in knowing -- let us assume, under

    10 suggestion, some kind of suggestion, the suggestion we

    11 talked about a moment ago, if he performs

    12 identification, I'm interested whether that individual

    13 intimately believes that he is speaking the truth and

    14 has had a clear identification, the subjective views of

    15 that individual that they have recognised the person.

    16 A. Yeah. That's an important aspect of all

    17 eyewitness testimony, the certainty, the conviction

    18 that the eyewitness has, the sincere and strong belief

    19 that he is speaking the truth. There is an enormous

    20 amount of research on the relationship between

    21 certainty, certainty of the witness, and how often the

    22 witness is correct -- and I'm not talking about two or

    23 three studies, but at least about a hundred or so.

    24 The bottom line of all those studies is that

    25 the relationship between certainty and correctness is

  23. 1very, very weak. There are many witnesses who are

    2 perfectly certain, and they are wrong. And there are

    3 many witnesses who are totally uncertain, but they are

    4 right. The bottom line is that the amount of certainty

    5 expressed is much more an aspect of the personality of

    6 that witness. Some are very certain witnesses --

    7 that's the way they are -- and some other people are

    8 always uncertain, even when they know the answer

    9 perfectly well. It's more an aspect of personality

    10 than an aspect of the quality of what they saw or what

    11 they remember.

    12 So it's quite likely that an eyewitness is

    13 totally sincere, totally honest, very convinced, does

    14 not assume that he or she can make a mistake and still

    15 is very wrong about it.

    16 Q. Thank you. Professor, I think that we have

    17 mostly covered all the areas that you touched upon in

    18 your expert report, and so finally I should like to ask

    19 you to tell us your final conclusion, that is to say,

    20 to tell us what your opinion is as to the truthfulness

    21 and correctness of the identification of Vlatko

    22 Kupreskic done by Witness Q, on the basis of the facts

    23 that you had at your disposal.

    24 A. My conclusion is that the most important

    25 factor is the viewing distance, and the viewing

  24. 1distance is prohibitive for making a good, reliable

    2 recognition. My data show that some subjects in

    3 experiments that have been done are still able to do

    4 that, but more than 50 per cent are wrong. As I said,

    5 the question whether that sort of a risk in

    6 identification is acceptable is totally up to the

    7 Court.

    8 Q. Deviation from that, you said whether it was

    9 reliable, unreliable, the degrees of reliability?

    10 A. Yeah. It's always difficult to express

    11 things in words that, to my mind, are perfectly well

    12 expressed in numbers. Whether, say, a probability of

    13 higher than 50 per cent that you are wrong, whether you

    14 would call that unreliable or slightly reliable or

    15 reliable, I think it's matter of words. What I have

    16 found is that to all probability, you must assume here

    17 that the likelihood of making a mistake at 60 metres,

    18 in the given conditions, is higher than 50 per cent. I

    19 don't call that reliable, but it's a matter of words.

    20 I would rather testify to the data that I have reported

    21 than to how you express that in words.

    22 Q. I think we have understood each other. Thank

    23 you very much, Professor.

    24 MR. PAR: Your Honours, I have no further

    25 questions. I should just like to propose that these

  25. 1two documents be tendered into evidence as Defence

    2 Exhibits D58/3 and D59/3.

    3 JUDGE CASSESE: Thank you. And I see no

    4 objection from the Prosecution. They are admitted into

    5 evidence.

    6 Counsel Pavkovic?

    7 MR. PAVKOVIC: Good morning, Your Honours. I

    8 think you were asking whether any other of the Defence

    9 counsel have any questions; I have one question for the

    10 Professor.

    11 Cross-examined by Mr. Pavkovic:

    12 Q. Good morning, Professor. I am counsellor

    13 Petar Pavkovic. Perhaps -- that is to say, I feel that

    14 this question should perhaps be given a broader, more

    15 complex answer, but I would be satisfied for the

    16 moment, and for these purposes, to remain at the level

    17 of a stand of principle. I should like to ask you

    18 briefly, and in principle, to tell us what the effect

    19 of time is, and the passage of time, on memory and the

    20 ability to reproduce what was once remembered.

    21 A. You're perfectly right that you're asking a

    22 rather complicated question, because obviously the

    23 answer depends very much upon what it is you want to

    24 remember. Like, a telephone number can be forgotten

    25 within a few seconds, but the fact that you won a case,

  26. 1which can be announced to you in the same amount of

    2 time, you will probably remember your whole life. So

    3 it is not easy to say what time is doing to memory.

    4 Some things will simply be never forgotten; time is

    5 irrelevant. Some things are very quickly forgotten,

    6 and everything in between is also possible.

    7 Now, we know that remembering a face that you

    8 have never seen before is, indeed, influenced by time.

    9 Studies that we have done related to bank robberies

    10 show that, say, after six weeks, for instance,

    11 remembering the face of the bank robber becomes

    12 problematic. I'm talking about six weeks. But

    13 remembering that you have seen someone whom you have

    14 known all your life, so that you don't have to remember

    15 the face of a bank robber, but only the name of a

    16 person, for instance, if you were in a bank and

    17 suddenly one of your colleagues comes in and appears to

    18 be a bank robber, well, that's rather surprising to

    19 you, and you won't forget that; not within six weeks,

    20 not within six months, and not even within six years.

    21 Now, there is a second problem, which is what

    22 we call the problem of rehearsal. To some things in

    23 our life, we are reminded all the time, and that means

    24 that in our memories, these things are refreshed all

    25 the time. Now, if we refresh some memories every day,

  27. 1we are simply not forgetting those things. Other

    2 things, to which we are never reminded, may gradually

    3 disappear.

    4 Now, the problem with a face is that it's

    5 very difficult to refresh the picture of a face in your

    6 memory if you are not shown the picture. So if you

    7 have to remember the face of a bank robber, but they

    8 have not caught the culprit yet, so you are not

    9 confronted with that face, in the meantime, the

    10 witnesses may forget the faces because they are not

    11 refreshed. But if you have to remember a name, you can

    12 refresh that yourself. Every time you tell the

    13 story: "This is what happened to me, this person did

    14 that to me," the name is refreshed. It can happen

    15 several times a day. And then there's no reason why

    16 memory would fade at all.

    17 So there are two factors, I think, which

    18 makes it rather urgent that if you have a question, you

    19 should be rather specific, because in general, the

    20 question cannot be answered.

    21 Q. Thank you, Professor. I'm satisfied with

    22 your answer. Everything else would require far more

    23 time and far more facts. Thank you very much.

    24 MR. PAVKOVIC: Thank you, Your Honours. That

    25 is all I wanted to ask.

  28. 1JUDGE CASSESE: Counsel Susak?

    2 MR. SUSAK: Mr. President, I'm going to ask a

    3 question now as to the inquisitiveness of the expert

    4 witness.

    5 My name is Luka Susak. I am the Defence

    6 counsel of Drago Josipovic.

    7 Cross-examined by Mr. Susak:

    8 Q. You mentioned the distance of recognition and

    9 the distance in viewing. I'm interested in knowing

    10 what is the greatest distance at which a person can be

    11 recognised? I have, of course, in mind that you said

    12 that sometimes there is absolute certainty, other times

    13 not, but I'm interested in hearing an answer. At what

    14 distance can an individual be recognised?

    15 A. Yes, it's good that you ask this question,

    16 because it gives me an opportunity to point again to

    17 the table, which is just the result of one study but it

    18 explains the principle.

    19 If you look at recognition rate at a distance

    20 of three metres, which is as far apart as we are now,

    21 probably, what you see is that even with perfect

    22 illumination, recognition is not perfect. There's

    23 always a likelihood that someone makes a mistake. The

    24 more one person resembles another, the more likely that

    25 is.

  29. 1There is simply no situation in which, as a

    2 psychologist, I could say, "There, no mistakes are

    3 made." Only, in such conditions, that the likelihood

    4 of a mistake becomes very, very small, so that for

    5 daily use we can say it's perfect.

    6 On the lower side, at the very long distance

    7 it's not going to zero. It's very difficult to say

    8 there it's impossible to make a correct identification,

    9 because even by guessing, you might be right.

    10 So the question is not at what distance is it

    11 impossible to recognise a person. The question really

    12 is, I think, at what distance are recognitions not

    13 reliable enough to be used as evidence. I phrase it

    14 that way because part of the problem is with me, I can

    15 say something about the rate, rate of mistakes, and

    16 part of the problem is with you, as lawyers, because

    17 you determine what reliable evidence is. But it's not

    18 a question of perfect recognition or no recognition at

    19 all. We're always dealing with something in between,

    20 and always the question of what is reliable enough to a

    21 court must be addressed. But for all practical

    22 purposes, that's what I have published on this

    23 business.

    24 I would say that recognitions at distances

    25 below 15 metres are about the best that a Court can

  30. 1get. There's little hope that you can improve upon

    2 recognitions at distances below 15 metres. Above 15

    3 metres is not perfect anymore, and if you want the best

    4 evidence, I would say then use recognitions at

    5 distances shorter than 15 metres. But I would never

    6 say all recognitions at distances above 15 metres are

    7 wrong, because they aren't. Above 15 metres, the

    8 question becomes how reliable do we want it to be. But

    9 that's your problem, not mine.

    10 Q. Thank you, Professor. Another short

    11 question, and it will be more concrete.

    12 Can an individual be identified at 200 metres

    13 if they are sitting down?

    14 A. Can you explain to me what you mean by "if

    15 they are sitting down"? Do you mean the face of that

    16 person is visible, because --

    17 Q. Yes, the face is visible but not the

    18 movements.

    19 A. In general, movement and posture are minor

    20 factors with respect to recognising a person. Unless a

    21 person has a very specific way of moving, for instance,

    22 because he's crippled or so, it is very difficult to

    23 recognise and very tricky to recognise a person from

    24 posture or movement.

    25 Really, the most important factor is the

  31. 1face, and if you look at studies that compare

    2 recognising living and moving persons with recognising

    3 the same person but only from a picture of their face,

    4 there's hardly any difference because the face is

    5 really decisive.

    6 With respect to posture and movement, there

    7 are so many people who have the same posture or move in

    8 the same manner that it's really rather tricky to

    9 accept identifications on the basis of those.

    10 So the question really is can you see the

    11 face, and as I have argued already for 60 metres, the

    12 likelihood that you would make mistakes at a distance

    13 of 60 metres is so high that I would never call that

    14 reliable, and at 200 metres it's obviously even worse.

    15 Q. Professor, I just asked for an answer to

    16 whether an individual can be recognised at 200 metres

    17 or not, an individual sitting down with their face

    18 visible.

    19 A. You're bringing me in a somewhat difficult

    20 position by asking me "Yes" or "No," because what I

    21 have explained is, unfortunately, not a "Yes" or "No"

    22 thing. I would never say that if you see a person at

    23 200 metres and you think, "This is so and so," that you

    24 would always be wrong. I'm only saying the likelihood

    25 of making a mistake at a distance of 200 metres is

  32. 1very, very high.

    2 MR. SUSAK: So as far as I was able to

    3 understand, an average person could recognise somebody

    4 sitting at a distance of 200 metres. I'm saying this

    5 out of my own curiosity, and I have no further

    6 questions.

    7 Thank you.

    8 JUDGE CASSESE: Thank you. Mr. Terrier?

    9 MR. TERRIER: Thank you, Mr. President.

    10 Good morning. I'm Franck Terrier, one of the

    11 counsel for the Prosecution. As you have experience

    12 with trials, you are fully aware that I will now

    13 proceed with the cross-examination.

    14 Cross-examined by Mr. Terrier:

    15 Q. First of all, Professor, could you tell us

    16 whether you familiarised yourself with the transcripts

    17 that were communicated to you by Mr. Krajina, I

    18 believe; the trial records, in other words?

    19 A. Yes. In the letter I sent to Mr. Krajina, I

    20 identified the pages of the trial records that I have

    21 used for familiarising myself with the situation that I

    22 was to study.

    23 Q. Professor, in that case, you were able to

    24 correct two involuntary errors in the introductory

    25 letter of Mr. Krajina. The first is that he said that

  33. 1a group turned around when they were shot at and looked

    2 at the soldiers for a moment, and the second error

    3 being that those soldiers were 60 metres away. I

    4 should like to underline that it follows from the

    5 record that the group didn't turn around but some

    6 members of that group, and this could affect your

    7 answer to question number 6 or, rather, 8, I think.

    8 The second remark I should like to make,

    9 Professor, at the beginning of this cross-examination,

    10 is that the witness spoke of a distance of 50 to 60

    11 metres, not a distance of 60 metres.

    12 I should also like to ask you to take into

    13 account the hypothesis that the distance might have

    14 been smaller than 50 or 60 metres, that it could have

    15 been 40 metres, because I should like to convey to the

    16 trial that we have new elements. That evidence is not

    17 presented in court now. I'm just presenting it in a

    18 hypothetical form to gain benefit from your experience

    19 and knowledge in these matters. So I am asking you to

    20 take into account this hypothesis of a distance of some

    21 40 metres.

    22 I should like to check that I fully

    23 understood your conclusions.

    24 You say that regarding recognition of a

    25 person known from before, a familiar person, the risk

  34. 1of error in identification increases with the distance,

    2 and particularly when the distance increases to above

    3 12 metres. And you say that at a distance of 40

    4 metres, the ratio between hit and false identification

    5 is 1 to 1, that is, that the risk of error is 50

    6 per cent.

    7 Did I understand you well, Professor?

    8 A. Yes. If I take your last two points, that's

    9 what I said.

    10 Q. You also say, at the end of your letter to

    11 Mr. Krajina, I think, that 60 metres is four times the

    12 required distance for recognition to be considered

    13 acceptable, so that the required distance would be 15

    14 metres. You also say that at 60 metres, identification

    15 remains possible, is still possible.

    16 To take up a question that has just been made

    17 by Attorney Susak in a slightly different manner, I

    18 should like to ask whether you can tell us, bearing in

    19 mind the physiological performance of the human eye,

    20 what is the maximum distance at which one can recognise

    21 a face without taking into account other factors, the

    22 memory suggestions and so on, simply the physiological

    23 performance of the human eye. What is the maximum

    24 distance?

    25 A. Should I address all the points you have made

  35. 1in order, so that we start with the fact that they all

    2 turned around, or do you want an answer first to the

    3 last question?

    4 Q. First the last question, please.

    5 A. Okay. I would say that the legal sciences

    6 are entirely different from my science. It would be

    7 highly interesting to study the physiological

    8 performance of the eye without memory and anything

    9 else. Unfortunately, in humans, the eye is connected

    10 to memory. We cannot disconnect it. It's not possible

    11 to answer the question of what the eye can do if not

    12 connected to the brain. It is connected to the brain,

    13 and it must be connected to the brain because

    14 recognition occurs in the brain, not in the eye. But

    15 at the same time, all other contributions that the

    16 brain can make are made during recognition. It cannot

    17 be helped.

    18 So as an example, your problem of at what

    19 distance can you recognise a person, take the following

    20 example:

    21 We know that through a door at 200 metres,

    22 say, two persons can enter. It's either you or the

    23 President of the Court and there are no other

    24 possibilities. I know that. Then at 200 metres, I

    25 will be quite safe in recognising whether it is the

  36. 1President of the Court or you, because I don't need to

    2 identify small details in the faces. I only need to

    3 identify very rough details and that's enough, and you

    4 are sufficiently different to do that at 200 metres.

    5 On the other hand, when two people who are

    6 more or less alike must be distinguished, I need to see

    7 details in their faces, and then it very soon becomes

    8 necessary to be at a distance of 15 metres.

    9 So the question is not what can the eye do

    10 but what information needs the eye, on top of other

    11 information that the brain already has, to make a

    12 correct identification.

    13 But it can't be helped that the problem is

    14 always that complicated, because we are not talking

    15 about the eye. The eye is only, say, the beginning of

    16 the process, it's the camera part, but the recognition

    17 is taking part in the brain on the basis of what

    18 information the eye is sending, and there's so much

    19 more information in the brain that the question cannot

    20 be answered in general.

    21 But if we are specific about the situation

    22 you are dealing with, which is people are fleeing, they

    23 are looking back, Witness Q is looking back, he sees

    24 four people, now the question is who are these people,

    25 and one he seems to recognise. Now, in principle, it

  37. 1could be a large number of people who are standing

    2 there. It's quite possible that they are people he's

    3 never seen before. But he seems to recognise one

    4 person he knows very well, and he is so certain about

    5 that that he testifies here in this Court it could not

    6 have been someone else.

    7 Well, in order to be reliable, you must make

    8 sure that it was not a person who looked rather like

    9 the person he knew before, and in order to do that, to

    10 make that distinction at a reliable-enough manner, he

    11 needs to resolve small details in the face, because

    12 there can easily be two people who look rather alike,

    13 but the details in the face differ when you look at

    14 small things like half a centimetre.

    15 So in my opinion, in order to give reliable

    16 evidence that it's this person he saw and not possibly

    17 any other person, he needed to resolve small details,

    18 and he could do that only at a distance of 15 metres or

    19 below. That's why I would say if you limit it to the

    20 question that you have here and not broaden it to very

    21 general questions about what people can do in all sorts

    22 of circumstances, you're talking about this condition,

    23 then I would say in this condition you need a distance

    24 of 15 metres or below.

    25 I'm sorry to give such long answers, but

  38. 1you're asking very complicated questions.

    2 Q. Professor, I listened to you with a great

    3 deal of attention and interest, but I'm still going to

    4 ask you another question which may be even more

    5 complicated.

    6 I see that there is a clear distinction, at

    7 least at this stage of our discussion, between the

    8 variables allowing one to say that recognition was

    9 precise or that there was a risk of error, and then on

    10 the other hand the question of reliability, that the

    11 reliability of recognition is something quite

    12 different.

    13 In my understanding, that is not up to the

    14 expert. It is not the responsibility of the expert but

    15 the responsibility of the Judges, who have to take into

    16 account other elements of assessment, among others, the

    17 fact that the presence of that recognised person in

    18 that spot was corroborated by other testimony, for

    19 instance. So the question of reliability is up to the

    20 Judges, whose sovereign right that is. At least that

    21 is my opinion. What I would like to look into are the

    22 variables which lead us to think that a recognition was

    23 precise or that there may be a certain percentage of

    24 error.

    25 So I come back to the question which I

  39. 1consider important, because in your reply, you

    2 mentioned considerations related to eye physiology. I

    3 think that an analysis is possible, because when we go

    4 to see an optician, we are asked to recognise A, B, C,

    5 and D, and we know that beyond a certain distance, we

    6 cannot recognise those letters.

    7 So my question is: Is there a distance

    8 beyond which recognition of a face is physiologically

    9 impossible because it is beyond the capacity of the

    10 eye, similarly to what we do when we visit an eye

    11 doctor and are asked to recognise letters?

    12 A. I think the example of the letters is a very

    13 good one to illustrate the problem that I have.

    14 At a very large distance, you may be

    15 presented with a letter, and if you just guess, you

    16 have a probability of 1 in 26 that you give the correct

    17 response. I, as a psychologist, cannot know what you

    18 did, whether you guessed or whether you saw it. I can

    19 only say if the distance increases, the performance

    20 levels go down to 1 in 26 correct, and probably they

    21 won't go down to zero. The same is with face

    22 recognitions. The performance goes down with distance,

    23 but they usually do not go down to zero because there

    24 is always other information in the head of witnesses

    25 that helps them to guess.

  40. 1Obviously, you don't want guessing

    2 witnesses. You want to get witnesses who testify to

    3 what they saw in a reliable manner, and therefore when

    4 you approach levels of performance that may be

    5 interpreted as just guessing performance, you should

    6 become very careful. You should become very careful

    7 even when the performance level is not zero, because

    8 the guessing level is above zero.

    9 Now, in the situation we are talking about,

    10 the question of guessing is not irrelevant, because if

    11 in that group of persons standing there and shooting

    12 there was someone he knew, how many could that have

    13 been, how many people were in the area? So if he felt,

    14 "I know some of them," then guessing might have led

    15 him to this observation, so the guessing level is a

    16 reality. The performance is not going down to zero.

    17 But quite rightly, you say that the only

    18 contribution that I can have is I can present you with

    19 some results of studies that we did. I hate to repeat

    20 myself, but the bottom line is, of course, I will never

    21 say that at distances, and we're not talking about

    22 miles and miles because obviously there is no

    23 recognition possible anymore, but at a distance we're

    24 talking about here, 60 metres, or 50, or 70, it doesn't

    25 matter so much, performance is still not at zero. It

  41. 1isn't. I can't help it. It's not at zero. But in the

    2 neighbourhood of 40 metres, already there are as many

    3 wrong identifications as correct identifications, and

    4 at longer distances, it's getting worse.

    5 Unfortunately, you're just, in your problem,

    6 hitting the area where it's not ideal, it's not even

    7 reliable, I would call, and it's not zero. I can't

    8 help it. That's the distance under discussion. That's

    9 how the situation grew.

    10 Obviously, it's the responsibility of the

    11 Court to say, "What criteria, with respect to

    12 eyewitness reliability, do we pose?" That's your

    13 problem. I can only sketch for you different

    14 likelihoods of making mistakes, and whether you think

    15 that's good enough, in the light of all the information

    16 that you have received in the meantime and I don't

    17 have, I will not and I cannot, of course, make that

    18 judgment for you.

    19 Q. I understand very well, Professor. I am

    20 going to put that question in a slightly different

    21 way.

    22 I am trying now to examine, and I'm asking

    23 you to say whether at a distance of some 60 metres,

    24 there is any obstacle linked to the physiology of the

    25 eye which makes recognition either impossible or

  42. 1extremely dangerous, and I'm referring to eye

    2 physiology again without referring to the brain or any

    3 interpretations.

    4 Going back again to the doctor's office, if

    5 the doctor asks me to recognise A, B, and Z, and if I'm

    6 trying to guess the letter, to guess the letter, that

    7 is only normal. Because this is an experimental

    8 situation, emotions, memory, feelings do not intervene

    9 or they do so to a minor extent, can we say that there

    10 is a physiological difficulty for the eye to recognise

    11 an object or the size of an object at a distance of 60

    12 metres?

    13 A. Yes. If you refer to the letters in the

    14 office of the ophthalmologist, the technician, the

    15 answer is quite simple. The letters are constructed in

    16 such a way that you need to resolve, as we say, one

    17 minute of arc, and that's the density of cones in the

    18 retina. That means for observation at 60 metres, that

    19 the thickness of the lines, of the letters, needs to be

    20 two centimetres. At 50 metres, the letters of the

    21 doctor are half a centimetre. Now, the doctor does it

    22 in a different way. He keeps the distance constant,

    23 because you are staying where you are, and he changes

    24 the size of the letters, because that's more

    25 convenience than increasing the distance of the

  43. 1observer. But the rule is the same. You can't see the

    2 letters in the office of the optician if you cannot

    3 resolve one minute of arc, which coincides with the

    4 sizes that I gave you. These letters are, of course,

    5 specially constructed to make it very clear whether you

    6 can see them or not see them. Unfortunately, faces are

    7 not entirely like letters; they are not constructed for

    8 optimal distinction between seeing or not seeing. So

    9 the question is much easier for letters.

    10 Q. Could we, for a moment, examine the table

    11 attached to the letter that you sent to Mr. Krajina.

    12 The two variables that were introduced are a distance

    13 of 3 to 40 metres, and illumination, 0,3 to 3.000 lux.

    14 Could you tell us what level of illumination

    15 corresponds to the daylight at 8.00 in the morning, to

    16 normal daylight, in the morning, in Europe?

    17 A. It depends on the date.

    18 Q. Yes, you're quite right, Professor. I'm

    19 talking of the month of April, in the northern

    20 hemisphere.

    21 A. Then probably -- you're probably very close

    22 to 3.000, so it's -- the right-hand column represents

    23 normal daylight. 300, which is the step below, then

    24 you are already in the dusk, so normal daylight would

    25 be represented by 3.000, and it can be a lot brighter

  44. 1if you have bright sun. The problem is that what you

    2 can do in laboratory, where you try to control the

    3 conditions, the best you can achieve is something like

    4 3.000, so that's why we didn't go any higher; but 3.000

    5 is a fair representation of a normal day, if you're not

    6 on, say, a beach, in the burning sun.

    7 Q. And 2 lux corresponds to what illumination,

    8 now?

    9 A. I didn't present a description of what it

    10 means. 0,3, the darkest, is in an area where there is

    11 no artificial illumination, in the night, with no

    12 moon. And then 2, you might say, is in the same area,

    13 with a very bad illumination, and then you slightly go

    14 on, gradually, to improving the situation.

    15 2, 3, and 5 are especially included because

    16 many questions that arise in court is recognising

    17 people in city conditions, and at night, and 2, 3, and

    18 5 are situations that you can encounter in city

    19 conditions at night, in various roadways, with a lot or

    20 not a lot of illumination. And that's why I chose 2,

    21 3, and 5, closer to one another, because that's a

    22 relevant area, and then I go, with somewhat larger

    23 steps, to the lighter part.

    24 Q. So to read correctly this table, we should

    25 say that at the level of 2 lux and a distance of 12

  45. 1metres, we come across a figure of 2,6, which means two

    2 correct recognitions against six incorrect

    3 recognitions. Is that the way we should read these

    4 results in the table?

    5 A. No, the numbers in the table are odds. They

    6 are always so much to 1. So the number that you

    7 mentioned is 2,6 to 1; 2,6 correct to 1 incorrect.

    8 It's always so much to 1. And if we go to the right,

    9 then at 10 lux, it's 28 to 1, and 67 to 1. Always so

    10 many correct to 1 incorrect.

    11 And what you see in the bottom line, where it

    12 goes below 1, so there, it can be like 0,2 to 1, which

    13 means 0,2 correct to 1 incorrect; that means far more

    14 incorrect to correct. So if the number is 1, the

    15 number of correct and incorrect identifications is the

    16 same, is equal. If you go below 1, there are more

    17 incorrect identifications than correct. And what you

    18 see at 3.000 lux, at a distance of 40, it's 0,8 to 1,

    19 which means it's almost 50-50. Almost 50-50. Slightly

    20 below, but that's not so important. These are, of

    21 course, experimental data.

    22 Q. Precisely, could you tell us what was the

    23 protocol of the trial that was applied in this test?

    24 A. The protocol is that people see a face under

    25 these conditions, and then immediately, without any

  46. 1delay -- so it's a retention time of zero seconds, you

    2 may say -- they have to point out on the display whom

    3 they saw. The display may have the face that they

    4 saw. That's the situation of a line-up where the

    5 suspect is indeed guilty, and then you can make a hit,

    6 because if you point out the correct person, that's

    7 what's called a "hit." The other half of the subjects

    8 see a display of persons, and the one face they saw is

    9 not present. That's the situation of a line-up in

    10 which the suspect happens to be not guilty; that's not

    11 the person they saw before. In that case, they can

    12 make a false alarm; if they still point out someone,

    13 that's called a false alarm.

    14 The numbers represented in this table are the

    15 ratio of hits and false alarms. That's the ratio of

    16 correct identifications and mistaken identifications.

    17 In order to do that, you need the two conditions of

    18 what we call "target-present line-ups" and

    19 "target-absent line-ups."

    20 Q. Who were the subjects who were looking, who

    21 were asked to identify?

    22 A. The subjects were students, so young people

    23 at our university, with perfect eyesight. So this is

    24 about the best subjects can do.

    25 Q. And the face that they were asked to

  47. 1recognise, was it a real face, or was it a photograph?

    2 A. They were photographs.

    3 Q. As for the persons they knew from before and

    4 they were asked to recognise or not recognise, were

    5 they photographs of members of their family, or just

    6 people they knew?

    7 A. No, as I explained in my letter, they were

    8 photographs of people they did not know. I have

    9 explained that in my letter, in the point -- on page 2,

    10 at the bottom paragraph. "The results in the appendix

    11 represent ..." -- and so on. And what I have pointed

    12 out in that letter is that what I want to illustrate

    13 with these data is the sudden drop that occurs between

    14 12 and 20 metres, because that drop is not related to

    15 anything in the brain, where the effect of persons

    16 known or not known to you is located, but to something

    17 in the eye. The eye cannot resolve the face any more,

    18 and that's why you get this sudden drop.

    19 If you're interested, you may compare the

    20 effect of what happens if you go from the right in the

    21 table to the left, where you go from much light to less

    22 light. There you see a gradual decrease of the

    23 numbers. There's not a sudden drop, because the eye

    24 does not react to lower light levels, a sudden drop,

    25 it's not a system of "go" and "no go." But if you go

  48. 1from the top to the bottom, there you see the sudden

    2 drop. You see it in all columns. It is there for 10

    3 lux as well as for 3.000 lux, and that is because you

    4 cross a certain -- say, "go/no go" system in the eye.

    5 That's the point I wanted to illustrate, and that

    6 simple biological piece of information is true for

    7 faces that you know and you don't know. It's simply

    8 not resolved any more. The eye stops. That's the

    9 point illustrated in this table.

    10 Q. I go back to the protocol of the trial to ask

    11 you for two or three points of clarification. The

    12 photographs that these students were asked to

    13 recognise, were there several, or was it one

    14 photograph? Were there several photographs shown?

    15 A. Yes, a large number of photographs was used,

    16 of course, for several reasons. One is, if you ask a

    17 student to recognise a number of people and they're

    18 always the same, it becomes very easy, so you can't do

    19 that. The other is that the way you test their memory

    20 is you present them with a photographic line-up of

    21 faces, and you ask them to point out, "Which is the one

    22 you saw?" For that, obviously, you also need a large

    23 number of photographs to pick from.

    24 Q. But my question was more specific. When this

    25 subject was shown a photograph, did he see only one

  49. 1photograph, or several in a line-up?

    2 A. The experiment, of course, consists of two

    3 stages. First you are confronted with one face, and

    4 then immediately thereafter, you are confronted with a

    5 photographic line-up in which you have to point out

    6 which of these people is the one you saw. So in step 1

    7 you see one face, and in the next step you see a

    8 line-up of several faces.

    9 Q. As we are interested in the recognition of a

    10 person known from before, could you tell us, what was

    11 the type of link that existed among those people on the

    12 photographs and your subjects, your students?

    13 A. As I explained on page 2 of my letter,

    14 there's no link. That's not the purpose of this

    15 experiment, and it's not the reason why I refer to it.

    16 The reason is only that -- the sudden drop between 12

    17 and 20 metres, where the eye cannot resolve faces any

    18 more.

    19 Q. I understand. You explained that in your

    20 letter. But we are interested in this very specific

    21 question, which is rather different from the one you

    22 dealt with in your trial, that is, recognition of a

    23 person known from before. Because now we, or rather I,

    24 have to try and check and verify whether this situation

    25 in the trial can be transposed to reality. I'm asking

  50. 1you, what were the faces which these students were

    2 asked to recognise? Whose faces were they? Were they

    3 film stars, people known? Was there an emotional link

    4 between those subjects and the photographs -- their

    5 mothers or fathers?

    6 A. No. No link, as I explained in my letter.

    7 There is no link. They are faces of people taken in a

    8 different city, so it's highly unlikely that they would

    9 ever have met these people before.

    10 (Trial Chamber confers)

    11 JUDGE CASSESE: Do you have a lot more

    12 questions, Mr. Terrier? Yes?

    13 MR. TERRIER: Yes, I'm afraid I have.

    14 JUDGE CASSESE: Because we have this problem

    15 with Judge May, who needs to preside over a hearing in

    16 another chamber. I understand, however -- yes?

    17 And then Mr. Par will probably have more

    18 questions, and I, too, have some questions.

    19 (Trial Chamber confers)

    20 JUDGE CASSESE: Mr. Terrier, take your time,

    21 because we have just decided to continue until 11.30,

    22 and I hope three-quarters of an hour will be

    23 sufficient.

    24 MR. TERRIER: I shall do my best,

    25 Mr. President.

  51. 1Q. Professor, I understood that the students

    2 were asked to identify photographs of people they

    3 knew. Am I wrong?

    4 A. Yes. As I explained -- I think I was rather

    5 careful to explain that -- in the bottom paragraph of

    6 page 2 of my letter: "The results in the appendix

    7 represent the identification of people not known

    8 before." Not known before. "There is a retention

    9 period of zero seconds, and it is therefore not wholly

    10 representative for the recognition of familiar people,

    11 but the sudden drop beyond a distance of 12 metres is

    12 highly relevant for the recognition of familiar people,

    13 because it represents a physiological limit of the

    14 human eye."

    15 That's the reason. So I don't think I left

    16 any uncertainty about that aspect. It is only the

    17 sudden drop that represents a mechanism in the eye that

    18 simply applies to all faces that you see, known or not

    19 known. If the eye cannot resolve them any more, then

    20 it stops, you see. Therefore, below -- the bottom part

    21 of the table is simply representing situations of faces

    22 that could not be resolved by the eye any more.

    23 Therefore, I think it's relevant to your question. It

    24 is within the limitation that I have expressed.

    25 Q. But, Professor, when you speak of

  52. 1identification of a face, it is identification in

    2 relation to what reference system? What does that

    3 student have to recognise? It is obviously my fault

    4 that I have misunderstood you; you have probably

    5 expressed yourself very well.

    6 A. In this experiment, the subject sees a face

    7 for about half a minute. Immediately thereafter, so

    8 with zero seconds interval, he sees a line-up and has

    9 to indicate which person in the line-up is the same as

    10 the face he has observed for about half a minute. And

    11 what you see is that. If you see a face -- at 20

    12 metres, for instance -- for half a minute, you have

    13 observed it as well as you could for half a minute.

    14 Immediately thereafter, you see that face again, but

    15 surrounded by some other faces, and you have to

    16 indicate who was it that I saw, that for instance, at

    17 an illumination level of 3.000, they are doing it about

    18 five times correct against one time wrong, whereas if

    19 it's 12 metres, they do it 90 times correct versus one

    20 wrong.

    21 That's a huge difference. It's an enormous

    22 step, an enormous loss of performance, and that loss of

    23 performance is related to the fact that the eye, during

    24 the first observation of half a minute, simply could

    25 not see the details in that face.

  53. 1Q. Thank you for this clarification. However, I

    2 have a further question. In this experiment, the

    3 subject, the student, did he necessarily have to give

    4 an answer, or could he have doubts or incertitude?

    5 Could the student say, "I don't know"?

    6 A. Yeah, definitely. The experience is that

    7 very rarely subjects do that, I must say.

    8 If I may add something, it's always clear

    9 that an experiment is not exactly the same as being in

    10 a war. If you are asked about details of the

    11 experiment, we will always hit, of course, the fact

    12 that an experiment is somewhat artificial and that you

    13 cannot create conditions of war in an experiment. For

    14 some topics, like studying emotions, that is, of

    15 course, highly relevant because if you cannot recreate

    16 the correct emotions, then the experiment is

    17 worthless. But here we are dealing with, say, a

    18 biological property of the eye, in which I feel that

    19 exactly creating all sorts of conditions that are

    20 present in war is not necessary. What is necessary is

    21 recreating the biological conditions.

    22 Exactly like when you go to an optician, he

    23 presents you some letters to see whether you can see at

    24 a long distance. And then, if you take the glasses

    25 that he prescribed, you go to drive your car, you will

  54. 1not meet any letters any more, and still the glasses

    2 will work, because we're dealing with a biological

    3 mechanism that can be tested by letters, although you

    4 want to apply it on the highway.

    5 In the same manner, the reasoning applies --

    6 at least to my mind -- that we present people with

    7 faces in a somewhat experimental condition, to test

    8 where the limit is that the eye can resolve. That

    9 limit will exist in wartime conditions equally well,

    10 because it's a biological piece of information.

    11 Q. And a last question regarding this table that

    12 you have submitted to us. Do I read it well by saying

    13 that at 3.000 lux, the ratio is below 1; when talking

    14 of a distance of 40 metres, it is 0,8; and at

    15 2 luxes, which means very bad lighting, and still at a

    16 distance of 40 metres, the ratio is 4 to 1?

    17 A. Yeah, you're right. And that illustrates, in

    18 a nice way, that the eye is connected to the brain.

    19 Since these numbers are ratios, there are two ways in

    20 which they can go down. One is that the upper part is

    21 going down or the lower part is going up. The lower

    22 part going up means false-alarm rates go up. Now, what

    23 happens in the 3.000 column is not only that the

    24 correct identifications go down, but also that the

    25 false alarms are going up, because people tend not to

  55. 1be so cautious when there is a lot of light, because

    2 they sort of have the feeling -- "There was lots of

    3 light. I had half a minute to look at this. It is

    4 rather silly for me not to recognise this face."

    5 So they have an inclination to give a

    6 response, instead of restraining themselves, as you

    7 have suggested is also an option. With 2 lux, they

    8 realise, "It's not so strange if I don't know the

    9 answer. The experimenter will not think I'm stupid if

    10 I say I don't know, because it's rather logical that I

    11 don't know."

    12 So at 2 lux, they don't make as many false

    13 alarms. And that piece of information is, of course,

    14 highly relevant for you, because what the Court has to

    15 decide is: This recognition that is presented in

    16 evidence, is that a hit, is that a correct

    17 identification, or may it be a false alarm? And what

    18 you should realise, that under daylight conditions,

    19 people tend to make false alarms. That's what I'm --

    20 because these are conditions that, to themselves,

    21 present good viewing conditions, so they are prepared

    22 to make a response. That's the danger of daylight

    23 conditions, and that's why you have this difference.

    24 I'm sorry it is so complicated, but in fact,

    25 if you look at a simple thing like a recognition,

  56. 1rather soon you realise it's a complicated process. It

    2 has to do with the tendency to believe that you are in

    3 good viewing conditions and therefore it's not

    4 illogical for you to state firmly that you have

    5 recognised someone.

    6 Q. What I'm having difficulty with, Professor,

    7 is that, for reasons that are certainly justified, you

    8 have two series of considerations. First, the

    9 physiological performance of the human eye, and,

    10 secondly, the interference of the brain, memory,

    11 feelings, the psychological interference. I must admit

    12 that that is probably my own problem, that I'm

    13 sometimes having difficulty making a distinction

    14 between the two. I'm still surprised to see that there

    15 are far more errors, or false alarms, as you say, under

    16 conditions of perfect illumination of 3.000 lux, than

    17 with a very poor lighting of 2 luxes and at the same

    18 distance.

    19 I find this paradoxical, and I'm wondering

    20 whether psychological interferences are a sufficient

    21 explanation, because these two different illuminations,

    22 the eye physiology being affected by bad visibility, as

    23 everyone knows.

    24 A. I think I must excuse myself, because I did

    25 not anticipate that you would be interested in such a

  57. 1thorough discussion of these data, because then, of

    2 course, I would have supplied the complete

    3 publication.

    4 As you see, this is Table 7. There are

    5 tables which have separate representations of the hits

    6 and of the false alarms, so that you can exactly follow

    7 why these ratios change, and then you can see that the

    8 effect that you call paradoxical, indeed, is caused by

    9 the fact that people make false alarms under good

    10 viewing conditions and far less false alarms under

    11 difficult viewing conditions.

    12 You can see the same effect if you look at

    13 the difference between 3 metres and 5 metres. What you

    14 see at 3 metres, for 3.000 lux, you see that's not the

    15 best performance. It becomes slightly better at

    16 5 metres, which is paradoxical. But that's not related

    17 to the hits; it's again related to the false alarm.

    18 Because if you saw a person at 3 metres, and then you

    19 say afterwards, "I don't recognise this person," then

    20 you look rather silly. So subjects have a tendency to

    21 at least point at someone, because they realise that

    22 the viewing conditions were perfect. And again, since

    23 the eye cannot be separated from the brain, we will

    24 always have such effects, but the sudden drop between

    25 12 and 20 metres is really caused by a sudden decrease

  58. 1of the hits.

    2 So if you're interested, and if it's relevant

    3 for the proceedings of your Court, of course I would

    4 supply the complete publication so that you possess all

    5 the information that there is in it, although, in a

    6 sense, I would also like to warn you a little bit that

    7 what I'm saying about the eye is of course not only

    8 based upon this one publication. We know the density

    9 of cones in the retina perfectly well; there is simply

    10 no discussion. Any basic textbook will give you that

    11 sort of information. But if it's relevant to you, I

    12 would of course be glad to supply the whole

    13 publication, and you can split all those effects out.

    14 If you need more explanation, then later on, I would be

    15 happy to return and do that for you.

    16 Q. Forgive me for asking this question, but

    17 since you relied quite extensively, it seems to me, on

    18 your experimental findings to say that facts that have

    19 to be tried by this Chamber, recognition carries a

    20 serious risk of error. My role as Prosecutor finds

    21 this to be a very important point in the trial; not the

    22 only one, but very important, still. As a member of

    23 the Prosecution, it is up to me to see whether this

    24 experiment, and this experimental knowledge that you

    25 are conveying to us, allow us to read and understand

  59. 1the reality facing this Trial Chamber.

    2 In view of that, I am asking you whether --

    3 don't you think that the relief of the face which is

    4 known, or which is to be recognised, the face in

    5 reality, such as it is, is it not an important element

    6 to be taken into consideration, and that this

    7 experiment, which you have conveyed to us, did not take

    8 that into account at all?

    9 A. Yeah, sure, there's a number of things to be

    10 said about that issue. The experiment is based upon,

    11 say, a whole variety of faces, not on one face, so the

    12 data are telling you something about recognising human

    13 faces in general. If there's one particular face with

    14 very outstanding features, then of course -- and you

    15 have a reason to believe that everything would be

    16 different for that particular face -- then you should

    17 do experiments with subjects and that particular face

    18 specifically, which can be done, of course.

    19 What I have done, however, is describe what

    20 would happen, and what the risks are, if we are talking

    21 about a face that is just a normal human face, with not

    22 such distinctive features that you would say for this

    23 particular face, everything would be different. And I

    24 have found no information, in the documentation that I

    25 have received, that we're dealing with a very specific,

  60. 1remarkable face with outstanding features, and I have

    2 no way to make a judgment about that. I have not even

    3 seen a picture of the person that was seen, so I have

    4 no judgment about it. But if you have reason to

    5 believe that everything would be different for this

    6 particular face, I think then you should request a

    7 specific study for that face.

    8 However, I still would like to warn you that

    9 at 60 metres, if you think that a specific face would

    10 be highly and reliably recognisable at 60 metres, it

    11 should be really a remarkably different face, with

    12 large details that are different from normal. To give

    13 you an example, if a person is a cyclop, has one eye in

    14 the middle of the front, that can be seen at 60 metres,

    15 rather obviously. But a rather big nose would already

    16 be difficult, because even big noses are not so big, so

    17 it should be a remarkably big nose.

    18 But I have simply no information about the

    19 specific face that we are discussing here. To make any

    20 judgment about that, I think it's your judgment to see

    21 whether there is reason to request a specific study, or

    22 at least reject this study. It's up to you.

    23 Q. Professor, I wasn't really speaking about a

    24 face with recognisable features, and still less a

    25 monster. My question is: Is it really the same thing

  61. 1to look at a photograph and to look at a real person at

    2 the same distance? Is it quite the same thing?

    3 A. Yeah, of course, we have studied that before

    4 running such an experiment, so one part -- also

    5 reported in this publication, I think, if you would

    6 have a complete copy -- is that first, of course, we

    7 made a comparison of seeing the real person and seeing

    8 a photograph of that person, under these conditions, to

    9 see whether that would not make a difference. Of

    10 course, the advantage of using photographs instead of

    11 real persons and presenting real line-ups all the time,

    12 instead of photograph line-ups, the advantage is so big

    13 that if you can do that, and you understand that this

    14 is a table that represents six, seven times nine

    15 experiments, in each cell is one experiment, so it's a

    16 huge study. So if you can do that with photographs,

    17 it's such an advantage that you would always do it, if

    18 its possible.

    19 Therefore we ran a pilot study to see whether

    20 the results would be any different if you used real

    21 faces, real persons, instead of photographs. The

    22 results were equal, so I don't think that is a

    23 particular problem.

    24 Q. For example, the context in which a face is

    25 to be recognised, can the background have any effect?

  62. 1Is it the same to recognise a face with a white

    2 background or with a forest in the background? Does

    3 the background play a role?

    4 A. Oh, definitely, definitely. Here we have

    5 used backgrounds with optimal contrasts, so that's the

    6 best possibility of recognising the faces. It's very

    7 easy to make it more difficult. For instance, say one

    8 important feature of people is their hairstyle, and if

    9 you use a background of the same colour as the hair, it

    10 becomes very difficult to recognise the hairstyle, and

    11 then one important feature is lost.

    12 These data reflect optimal conditions in

    13 which things like the hairstyle, for instance, can be

    14 optimally seen, so you can easily make it much more

    15 difficult and the results get worse.

    16 Since I have simply no information about the

    17 background against which, say, in your case the face

    18 was seen, you really need a careful reconstruction,

    19 because if people are standing in front of a house, if

    20 they stand in front of the white wall of the house,

    21 it's totally different than if they stand in front of

    22 the black window of the house. Still, the distance

    23 would be 50 centimetres to the right or to the left.

    24 So I have not even tried to reconstruct for

    25 myself what the situation would be. I've only looked

  63. 1at let's assume that it's optimal. Then still we've

    2 got this problem.

    3 Q. Thank you. I should like to go back to the

    4 effect of fear and danger that you referred to.

    5 You said, if I understood you correctly, that

    6 a situation of fear and danger can limit the field of

    7 observation, while at the same time increasing the

    8 attention, the focusing of that subject on that field

    9 of vision.

    10 I wanted to ask you, and I think you already

    11 have answered up to a point --

    12 MR. RADOVIC: Mr. President, my client would

    13 like to be excused for a moment, if he may.

    14 JUDGE CASSESE: Mr. Terrier, you may

    15 continue.

    16 MR. TERRIER:

    17 Q. I wanted to ask you to tell us whether this

    18 effect which you have explained, that of fear and

    19 danger, is valid for all individuals, for all persons,

    20 or, on the other hand, are certain persons prone to

    21 lose all their capacity of observation in a situation

    22 of fear and danger?

    23 A. Well, to begin with, I think I have clearly

    24 stated that on the matter of fear, I have no opinion on

    25 what effect it could have had in this particular case.

  64. 1It could have improved the observation, and it could

    2 have worsened the situation. I have simply no idea,

    3 because it's very difficult to predict where the

    4 witness would look.

    5 Now, individual differences are mostly

    6 influencing the question whether, in a particular

    7 situation, a person will have fear, because if you are

    8 used to a situation, you might have less fear than if

    9 that situation is completely new to you. So individual

    10 differences are related mostly to in which situations

    11 will the fear occur. But given the same amounts of

    12 fear in various people, the effects will be more or

    13 less the same.

    14 So the question in this case would be, "How

    15 much fear will there be in this particular witness,"

    16 and I have no way of knowing that. I don't even know

    17 the witness. The question is not so much, "And if

    18 there was fear, would there be the same effect as in

    19 other people," because these effects of fear are rather

    20 universal. The biggest difference with respect to

    21 people is some have fear and some don't.

    22 Q. I understand what you are saying, but I

    23 should like to respectfully note that they are not

    24 responsive to my question.

    25 To go back to the facts that we have to

  65. 1judge, this was indisputably a situation of danger,

    2 because the group of people who were being shot at were

    3 escaping, about to flee, and they were exposed to

    4 threat. None of them were armed. They were all

    5 civilians. Some were women, others were children. So

    6 without any doubt, we're facing a situation of danger.

    7 Let us not speak of fear. Let us just focus

    8 on the question whether this situation of danger, which

    9 is undisputed, what effect it could have had on the

    10 capacity of observation and attention of those people,

    11 and did it differ depending on the personality of

    12 each? Of course, I'm not asking you to analyse the

    13 individual effect, but could there have been a

    14 difference?

    15 A. The difference, if you assume the same amount

    16 of danger and therefore -- which is not a necessity,

    17 but let's just, for the sake of argument, assume the

    18 same amount of fear in these people, then there is

    19 still the question, "What will they focus on?" One

    20 person may focus on the arms that are pointed at them,

    21 and other people may focus on the faces behind those

    22 arms, which is a different thing. Others may even

    23 focus on totally different areas where they expect that

    24 some other danger will come from. So the differences

    25 with respect to how people would react, given that they

  66. 1have the same amount of fear, in my opinion would in

    2 the first place be on what will they focus on.

    3 To give a very simple example, it has nothing

    4 to do with emotions and it happens to me all the time,

    5 if I'm visiting other people and I come back, my wife

    6 always knows what the other women were wearing and I

    7 don't. I've seen the same, but I've not focused on the

    8 same. There is some difference between men and women

    9 with respect to what they pay attention to.

    10 Now, obviously since we're here, we're

    11 talking about men, women and children. They may pay

    12 attention to different things, and then the fear, that

    13 will have a remarkable effect, because paying attention

    14 to the one thing rather soon means that you did not pay

    15 attention to the other things.

    16 So, indeed, you're quite right, there may be

    17 huge differences as to what they paid attention to.

    18 The only thing I want to stress is that for me, as an

    19 expert, it's not a subject I can really tell you much

    20 about because I have no basis for deciding whether the

    21 witness in this case paid a lot of attention to that

    22 face or not. It's quite possible that he paid a lot of

    23 attention to that face. It's also possible that he

    24 didn't. I have no way of knowing. That's not a

    25 question, I think, that you can pose to an expert who

  67. 1was not there.

    2 Q. Yes. But, Professor, don't we have there the

    3 answer to the question number 6 posed to you by

    4 Mr. Krajina, why other people in the same group did not

    5 recognise the face in question? You said that it was

    6 due to the distance. Couldn't the answer simply be

    7 because other people may have been looking at something

    8 else, their attention may have been drawn to some other

    9 details?

    10 A. You're quite right. It's quite possible that

    11 these other people were not looking at this face. But

    12 what I wanted to say is that even if they had

    13 concentrated on this face, still the distance of 60

    14 metres would have made it rather unlikely that they

    15 would have recognised anyone.

    16 Maybe it's a bad habit of scientists, but if

    17 there's a simple answer that makes it not necessary to

    18 go into the more difficult things, then we are always

    19 quite satisfied and say, "Well, we take the simplest

    20 argument, and that relieves us of going to a far more

    21 difficult thing about which I can tell you very little.

    22 So why would I speculate on the more difficult thing if

    23 I can tell you something that's rather reliable on the

    24 simple question of distance?"

    25 So you're quite right, and if you want to

  68. 1make that speculation, I'm the last person to stop

    2 you. I can only say I have no way of knowing where

    3 these people looked.

    4 Q. I will not engage in any kind of speculation,

    5 Professor. I'm just trying to take advantage, from

    6 your experience and your knowledge, to be able to

    7 better interpret the extremely complicated real

    8 situation that this Trial Chamber has to judge.

    9 Now to go to another question, the question

    10 of the degree of familiarity between the person who is

    11 doing the observation and the person to be recognised.

    12 Wouldn't a high degree of familiarity

    13 facilitate, at a distance of 40 or 50 or 60 metres, the

    14 recognition of the face?

    15 A. Well, I would say beyond a certain level of

    16 familiarity, the differences are not so important

    17 anymore. There are large numbers of people whom we

    18 know and whom we will recognise in half a second, and

    19 they don't have to be more familiar to be recognised by

    20 us. So degrees of familiarity, at least they have not

    21 been studied, so on the basis of scientific research,

    22 there's very little to say about it.

    23 But I think I have to come back to the same

    24 statement again. Even if there is a high degree of

    25 familiarity, beyond a certain distance you're going to

  69. 1make mistakes. In the end, you may even think that at

    2 a certain distance that person is your wife, and she

    3 isn't. Some distances are simply too long for reliable

    4 identifications.

    5 Another problem is, of course, that -- but I

    6 don't want to complicate the matter, of course -- we're

    7 talking here about a familiar person in a rather

    8 unfamiliar situation, and I don't know much about, and

    9 I've also written that in my letter, about, for

    10 instance, any head gear the person was wearing or

    11 anything unusual about the person whom you knew under

    12 different conditions, so I find it very hard to address

    13 the issue of familiarity at all without much more

    14 information about that exact situation.

    15 Therefore, again I would come back to the

    16 essential statement that 60 metres is simply

    17 prohibitive for reliable identifications anyway.

    18 Q. My question was the following: You told us

    19 that at 60 metres, identification is not impossible but

    20 it carries a risk of error. My question was whether a

    21 considerable degree of familiarity that we are going to

    22 suppose between the subject and the witness does not

    23 reduce that risk of error.

    24 A. Not necessarily, and we have to go back to

    25 the problem of hits and false alarms.

  70. 1High familiarity, in the first place, means

    2 that it is a response that is rather on the front of

    3 your mind. It's one of the responses you would first

    4 make rather than another response, which means that

    5 familiarity may increase the number of hits, which

    6 means if it is really the person you think it is, you

    7 are more likely to identify him, but if it's not him,

    8 are you more likely to make a false alarm, and

    9 therefore not necessarily the ratio of the two will go

    10 up.

    11 But this is a theoretical answer, of course.

    12 I understand that. But there is simply no research in

    13 which, say, degrees of familiarity are used in an

    14 experiment to see what exactly hits and false alarms

    15 will do. I will only warn you not to assume that just

    16 for logical reasons, say, the numbers should go up. It

    17 could go down as well.

    18 Q. Professor, you told us and you have written

    19 in your report that the pertinent features that the eye

    20 has to resolve to be able to make recognition are

    21 typically 0,5 centimetres, and you added that the

    22 smallest details which can be resolved by the human eye

    23 at a distance of 60 metres are of the order of two

    24 centimetres, and therefore we are facing a

    25 physiological difficulty there. I would like to ask

  71. 1you, and I address you as a psychologist and your

    2 professional experience in the field, what are the

    3 features of a face which need to be seen and recognised

    4 to permit identification, and do all features in the

    5 face contribute equally to an identification?

    6 JUDGE MAY: I seem to remember we've been

    7 through this. We had discussions of the nose and that

    8 sort of thing. I'm just wondering how helpful this is

    9 to the Chamber, to go into all this detail.

    10 MR. TERRIER: My question, Your Honour, was

    11 the following: The expert has told us that details of

    12 a certain size need to be identified. My question was,

    13 "Which are the features and characteristics of a face

    14 that need to be recognised, and what should their size

    15 be for that identification to be possible?" It seems

    16 to me, and maybe I'm wrong, maybe I'm going beyond my

    17 duties here, but it seems to me that I can contribute,

    18 to a certain degree, to a better understanding of this

    19 matter by Your Honours.

    20 I think that this is a question that can be

    21 usefully put to the witness, but of course if you

    22 consider it quite useless, I will withdraw it.

    23 JUDGE MAY: It's a matter for you and I'm not

    24 going to stop you, but please allow some common sense

    25 in the matter.

  72. 1MR. TERRIER: Very well, Your Honour.

    2 Q. Professor, as a psychologist, could you tell

    3 us which are the facial features that need to be

    4 identified for recognition to be possible and whether

    5 these features, in themselves, contribute to an

    6 identification?

    7 A. There is a lot of misunderstanding about what

    8 is important to recognise a face, because people tend

    9 to believe that it is the eye or the nose or the mouth

    10 or something, whereas in fact it's the relationships

    11 between those things, the distance between things, the

    12 distance between the eyes, the distance of the eyes

    13 related to the size of your head and so on, so it's a

    14 matter of perceiving the relationships and not

    15 perceiving, say, eyes or noses. A slight change in

    16 relationships, placement of things, makes things

    17 totally different.

    18 So it's very hard to say, "Well, I saw the

    19 eyes. That's enough," or, "I saw the nose. Isn't that

    20 enough?" It's the relationship between things that

    21 matters most, that makes it so intangible to describe.

    22 If you ask a witness, "Well, you recognised him. How

    23 did you recognise him, then," or, "What did you

    24 recognise then?" Sometimes witnesses answer those

    25 questions, "I recognised the eyes," or, "I recognised

  73. 1the nose," but, in fact, witnesses don't know what they

    2 need to recognise a face because it's relationships

    3 between things in the face, and that's rather

    4 abstract. That's where half centimetres matter.

    5 Q. Let me put my last question to you,

    6 Professor, and that is related to suggestion.

    7 You said that the recognition of a person

    8 that one knows from before is an immediate phenomenon,

    9 and a question put to you by Mr. Krajina, you said that

    10 suggestion plays a role, relating this to the fact that

    11 the witness did not immediately give to his

    12 interlocutors the name of the person that he

    13 recognised.

    14 In the circumstances that you familiarised

    15 yourself with, the circumstances of the time and place,

    16 does it seem really unusual that the witness did not

    17 immediately inform the people around him of the name of

    18 the person that he had recognised?

    19 A. Of course, you're quite right. It would have

    20 helped a lot if I would have known that immediately he

    21 said or cried, "It's so and so," because that would

    22 mean there's an immediate recognition, and after that,

    23 there is no inference of suggestion anymore because the

    24 recognition is made, period.

    25 Now, I am in a situation in which I was told

  74. 1that he reported it much later. On that basis, I

    2 cannot decide whether he recognised immediately or

    3 not. I only know he did not report it immediately.

    4 It's impossible for me to decide whether he recognised

    5 immediately but had good reasons not to give away his

    6 information or he recognised not immediately but

    7 gradually became aware of what he had seen. I cannot

    8 make that distinction on the basis of what is provided

    9 to me, and it's a highly-relevant question and I think

    10 you have to answer it. But on the basis of the

    11 information I was given, I can't answer it.

    12 Q. Therefore, the silence of the witness for a

    13 certain period of time, in itself, doesn't necessarily

    14 mean that he was under any suggestion?

    15 A. No. It opens the possibility. It has to be

    16 sorted out, what happened.

    17 MR. TERRIER: Thank you very much, Professor,

    18 for having answered my questions.

    19 I have no further questions, Mr. President.

    20 JUDGE CASSESE: Thank you, Mr. Terrier.

    21 Counsel Par?

    22 MR. PAR: No more questions, Mr. President.

    23 JUDGE CASSESE: Thank you.

    24 Any questions? I'm afraid I have a short

    25 question.

  75. 1Professor Wagenaar, I have realised that you

    2 have focused on the face of the person to be

    3 recognised, and at one point, I took some notes, you

    4 played down movement and posture. I wonder whether

    5 this is because you were under the influence of your

    6 own study, which was about faces and faces on

    7 photographs, because speaking as a layman, as a man on

    8 the street and of my own experience as somebody who is

    9 used to walking not here but in another place very

    10 similar to the country we are talking about, where

    11 there are hills and woods and so on, I can say that

    12 very often you can see from a distance, say even 50,

    13 60, 70 metres, people whose face is not very clear, but

    14 then one may pay attention to the fact whether the

    15 person is short, is tall, is bald or has a lot of hair,

    16 but even more important, were they slim or fat or

    17 burly, so it is this combination which may prompt me to

    18 say, "Aha, well the face is not so very clear, but his

    19 whole body does match this name," of course on the

    20 assumption that this person is familiar to me, a person

    21 whom I have seen for ten years, for instance, in that

    22 particular area. So this is what happens to me, for

    23 instance, when I walk in Tuscany sometimes and I see

    24 people, and as I say, because of this combination of

    25 various elements, I am in a position to recognise this

  76. 1person.

    2 So my question is: Is it proper and correct

    3 to also emphasise the role of the other elements which,

    4 together with the face, may allow you, enable you, to

    5 say, "Yes, this is the man whom I know and he is there

    6 up on the hill, and I can see him even if he's in a

    7 wood, in a clearing in a wood, but I can see him fairly

    8 well"?

    9 A. Of course, you're quite right, Your Honour,

    10 that such facts exist. But I focused, I hope, not so

    11 much on the studies I did, but on the situation as it

    12 was presented to me, and the following features are

    13 important: There are a number of people standing there

    14 at a distance of 60 metres. Now, to decide what their

    15 size is, you need some sort of reference. It's not

    16 obvious to me that a good reference point was available

    17 so that you could see whether they were short or tall.

    18 The size of people is very hard to distinguish if you

    19 have no reference point.

    20 The following point is that I have no

    21 information that the size of the person who was

    22 observed is remarkable in any way, which means that

    23 even if you perceive the size correctly, that doesn't

    24 mean that it definitely must be that one person,

    25 because if many people have the same size, then still

  77. 1it doesn't help you so much to perceive size correctly

    2 with the aid of reference points.

    3 The same as for posture. You're quite right,

    4 some people are highly recognisable because of their

    5 posture, because they are fat or slim or crooked or

    6 whatever. The question is if someone is just normal,

    7 falls on the average, how could you recognise such a

    8 person on the basis of posture? And experimental data

    9 shows that that is very, very difficult.

    10 The experiments run, more or less, as

    11 follows: You make a comparison of recognition scores

    12 in a number of situations. One is life, moving. One

    13 is life, stationary, so movement is excluded. The next

    14 is on television, moving. Then on television,

    15 stationary. Then on a photograph, total body, and

    16 finally on the photograph, only face. What you see, if

    17 you compare those conditions, that the differences are

    18 very small. The contribution of movement, posture,

    19 size, are really very small compared to what you can

    20 tell from a face.

    21 Now, a further condition is here, that I was

    22 told he looked in a moment, and the question is how

    23 much movement of people can you see in a moment if

    24 you're talking about one fixation, and that's what I

    25 have reported in my letter. In one fixation, you can't

  78. 1see any movement, you just see a still picture, and

    2 then there is very little to tell about movement. So I

    3 have not concentrated about these elements of what I

    4 was to say, because the face is so much more important

    5 than the other things in this situation that I think

    6 perceiving the face would be decisive.

    7 JUDGE CASSESE: Thank you. Thank you so

    8 much.

    9 I assume there is no objection to the witness

    10 being released.

    11 Professor Wagenaar, we are most grateful to

    12 you for testifying in court today, and you may now be

    13 released.

    14 Before we adjourn, let me simply remind the

    15 parties that we will reconvene on the 21st of June for

    16 one week. We will then skip the following week, and

    17 then we will resume our proceedings on the 5th of July

    18 until the 23rd of July, just as a reminder.

    19 So the hearing is adjourned.

    20 (The witness withdrew)

    21 --- Whereupon the hearing adjourned at

    22 11.35 a.m., to be reconvened on

    23 Monday, the 21st day of June, 1999,

    24 at 9.00 a.m.