Aids to recall / recognition: identikit and identity parades
Goldstein and Chance (1971) tested subjects for their recall of photos of women’s faces, snowflakes, and inkblots. Participants were shown 14 photos from each set, and tested immediately afterwards, and then again after 48 hours. The results showed that accuracy of recall for faces was good — 71%, as against 48% for inkblots, and 33% for snowflakes. Facial recall and recognition are, however, quite complex aspects of memory. For instance, most of us can easily recognise a familiar face, but if we were asked to describe that face in detail would experience some difficulty. Moreover, while we may often recognise a face as familiar we may not be able to pinpoint why, or recall the person’s name.
Recognition of faces is poor if the face changes between the encoding and the presentation of possibilities. This could be a change in glasses, hairstyle, beard or even expression. Patterson and Baddeley (1977) compared the accuracy of recall of a face that had changed in some way between the first and second time the participants saw it. For example, a change of wig reduces the accuracy of recall to 50%, while a change of wig and beard leads to only 30% accurate recall. These figures compare to 70% accuracy when the face does not change.
The accuracy of face recall is also influenced by: length of time since the face was seen, the seriousness of crime, the number of previous encounters with the suspect, and witness characteristics (like attention to detail).
The most confusing method for recall is to show ‘mugshots’, then have an identity parade. This leads to confusion between recognition and episodic memory. In other words, the witness may recognize a face in the identity parade, but not know if it comes from the original event or from the ‘mugshots’.
Face recognition for familiar faces
The recognition of familiar faces and the naming of the person can be seen to have three stages.
1. The face is compared with a set of stored descriptions called ‘face recognition units’ (FRU), and this produces a feeling of familiarity or not.
2. The memory store is activated to recall facts about the person.
3. The retrieval of the name of the person is then made.
The research has tended to concentrate on whether the stored descriptions are based on individual features or the whole face. One possibility is a representation of how each face differs from the average prototype, and thus distinctiveness is the key (Bruce 1988).
Using computer images, Haigh (1986) found that the shape of the head was most important, followed by the eyes and mouth in full-face recognition, while the nose is more important in profile recognition.
In real life these problems associated with facial recall can have serious consequences. A vivid example concerns an Australian psychologist, Donald Thompson, whose research attracted some media attention, and he appeared in several TV programmes to discuss his findings. A few weeks later, however, he was picked up by the police, put in a line-up, and identified by a woman who claimed he had raped her. It subsequently emerged that the time of the rape had coincided with Thompson’s participation in a live TV discussion, providing him with an excellent alibi. The woman had been attacked while this programme was on air, and although she correctly identified Thompson’s face, having emotionally associated it with the event, she wrongly assigned it to the rapist. This can be regarded as unconscious transference of memory traces.
Media coverage of crime can play a part in this type of unconscious transference. For instance, Ainsworth (1995) showed participants a local news story about a series of sexual assaults which included two photos, one a photofit of the suspect and the other a photograph of a ‘good Samaritan’ who had helped one of the victims. A week later the participants were asked to select the suspect from a selection of six photos. One group was shown a selection containing the photofit of the suspect, a second group was shown a selection containing the photo of the ‘good Samaritan’, while the third group was shown a random selection. The first group picked the suspect on almost 40% of occasions, while the second group incorrectly selected the face of the ‘good Samaritan’ on 50% of occasions. The chances of selecting the suspect or the ‘good Samaritan’ were roughly equal, suggesting that unconscious transference was playing a part.
Labelling a face can also influence how people recall facial features. Shepherd, Davies and Ellis (1978) asked participants to view a photo of a male face for 30 seconds and then asked them to construct a photofit. Half of them were told the face belonged to the brave captain of a lifeboat, while the other half was told the face was that of a mass murderer. The subsequent photofit pictures were quite different, with the face of the alleged mass murderer judged to be more cruel, unpleasant and unintelligent.
Photofits were first introduced in the UK in 1970 and involve trained operators selecting alternatives for specific facial features to match a witness’s verbal description until they have produced a type likeness. There are several ways in which researchers have attempted to improve on this method. One is the use of computers to produce from the witness’s description a good pictorial likeness of the suspect, known as an E-FIT. However, the original E-FIT still built up a face on a feature-by-feature basis: as the witness gave a description of, say, the eyes, the computer chose the best set of eyes to fit this description, and so on. The witness did not see the face until it was completed. Researchers from the Face Processing Research Group have recently pioneered a new system of compiling an image of criminal suspects based on the idea that an improved image would be produced by allowing the witnesses to watch the face build up. It is very important that the features are seen as part of the whole face, so a cartoon outline and features are used to replace those elements that have yet to be described. In addition to this, if possible, the evidence from several witnesses is used to create a more accurate image of the suspect’s face.
While these methods are widely used there has been little in the way of their evaluation, nor has there been much recognition of the possibility that producing such a likeness may interfere with a witness’s original memory.
When witnesses experience problems recalling faces they may be presented with a ‘mugshot file’ which is a collection of photos of people already known to the police, on the assumption that these photos may act as a prompt. One of the problems associated with mugshot files, however is that the witness may feel under pressure to make a selection even though they do not feel particularly confident. This was certainly the case with the child participants in a study by Peters (1987). Another problem is that the witness is being asked to view a static representation of a suspect whom they saw live.
The same problems can occur when a witness is presented with a photospread or a show-up. A show-up is the presentation of a photo of one suspect for the witness to identify, and is the least satisfactory form of identification, though as Ainsworth (2000) points out, one form of show-up is used consistently in courtrooms without question. This occurs when witnesses are asked to point out the perpetrator in court, but it presumes automatically that the right person is in the dock, since the witness is highly unlikely to choose someone in the public gallery. With show-ups witnesses may be led to believe that the police are very confident about the suspect since this is the only one being presented. Yarmey (1992), however, was able to show that only 57% of witnesses in a show-up were able to correctly identify a person with whom they had interacted two minutes earlier. A photospread is more effective than a show-up, as it involves the presentation of at least 12 faces all resembling the suspect. Much, however, will depend on the fair selection of foils alongside the suspect, and the witness may still experience pressure to make a selection, possibly being unprepared to admit that the suspect is not present.
Photospreads would tend to be used in situations where the police have a suspect in mind, but need a witness to confirm the identification. A typical procedure would involve a witness viewing an array of perhaps twelve photographs and being asked if they recognised anyone in the array. If the witness indicated that they did recognise anyone then they should be asked to say which photograph they recognise and from where. Photospreads have a number of advantages over the procedures discussed so far. For example, they are preferable to mugshot inspections in that they allow the witness to peruse a much smaller number of photographs before making a decision. They are also fairer than show-ups because the witness is asked to make a decision about an array of possible alternatives rather than just about one face.
However, photospreads are not without their own problems. For example, a witness who has seen a ‘live’ perpetrator may have difficulty in relating that image to a static photograph. Further, the photograph itself may not be a particularly good likeness, or may have been taken when the accused’s appearance was somewhat different. Many studies carried out in the psychology laboratory suggest that people can be quite good at identifying a face seen previously (Cutler et al., 1994). However, many of these studies lack ecological validity and their results are perhaps not easily related to real life studies. For example, most lab-based studies involve showing subject-witnesses a photograph and then later asking them to identify the same photograph from an array. In such cases, however, the target person’s appearance is identical in both viewings, making recognition somewhat easy. Furthermore, most studies of this kind will use an array which does contain the photograph shown previously. In real criminal investigations it is possible that on some occasions the police will have the wrong suspect in mind and will thus show the witness a photospread which does not contain the real perpetrator.
It would be naïve to presume that on all such occasions the witness will simply tell the investigators that the perpetrator is not present and that they should start looking elsewhere. The pressures on a witness, especially one who has been a victim, may encourage him/her to guess or to point to the photograph which is most like the face of the real perpetrator. Such ‘guesses’ will not, however, be distributed randomly across the twelve photographs presented. In all likelihood the police will have plumped for a particular suspect because they match the verbal description given by the witness originally. If one face in the photo array matches all the elements provided by the witness, it is quite likely that the witness, even if unsure, will choose that photograph. But, of course, this does not necessarily prove that the face which is picked out is that of the real perpetrator — it may simply be that it matches the description more closely than do the others.
Although the regulations governing the conduct of identifications would not allow investigators to use foils whose appearance was completely different from that of the suspect, there will inevitably be some foils which can be rejected immediately because some aspect of their appearance is at odds with that of the real perpetrator. Furthermore, the fact that the witness can view all the photographs at once makes the procedure similar to a multiple choice examination question. The witness may go over the array a number of times and gradually eliminate the less likely foils until they are left with perhaps just one or two from which to choose. In such situations, an identification would not necessarily prove that the face picked out was that of the real perpetrator, but instead may simply signify that it was the one whose appearance was most like them. Laboratory studies which have used a ‘target absent’ array show that people do on occasion pick out an innocent person, rather than admit that they are unable to spot the face seen earlier. This can be a particular problem with younger children (Davies et al, 1988) who may feel pressured into picking someone out even when they are unsure.
The authorities are aware of some of the potential problems of photospread identifications and in many cases will try to prevent mistakes from occurring. For example, it is now routine practice for witnesses to be told in advance that the person whom they saw ‘may or may not be in the photo array’ and that witnesses should only identify someone if they are certain. However, such warnings may be ineffectual when a victim-witness is highly motivated and wants desperately to see his/her attacker brought to justice. Regulations also dictate that when a photospread is used it should be made available to the court so that jurors and defence counsel can see for themselves whether the procedure was fair.
Photospreads can have some advantages over the traditional live identification parade. For example, photospreads may be considered more suitable for young witnesses or for those who are particularly nervous. For such individuals, attending a live ID parade might be particularly nerve-wracking and they may find the mere physical presence of a perpetrator intimidating. In such situations, the real perpetrator may be more likely to be identified if witnesses view a photo-array than if they attend a live ID parade.
Identification parades (line-ups)
Perhaps the best know type of formal identification process is the identification (or ID) parade. In such procedures a suspect stands among a number of innocent foils and a witness is asked to inspect the parade and then to decide whether the perpetrator is present. The technique is in some ways similar to that of the photospread and as such is prone to the same types of errors. Thus, a witness may feel under pressure to pick someone out even if they are unsure; the appearance of the foils may allow the witness to eliminate some immediately, etc. As with photospreads, there are regulations which govern the fair conduct of ID parades, including the need to inform a witness that the perpetrator may or may not be present and that they should make an identification only if they are sure. It is also normal for the accused’s legal representative to be present at the parade and for the whole procedure to be video-recorded. However, guidelines and advice can never guarantee that mistakes will not be made. As has been noted recently:
Such guidelines may have eliminated some of the more questionable tactics used in the past, but as some recent cases of wrongful conviction have shown, there is still room for bias and error to creep in.
(Ainsworth, 1998: 92)
There are a number of distinctive aspects of live ID parades which may contribute to possible errors. One obvious consideration is the number of foils who should be put into a parade in order to make the procedure fair. Rules concerning this vary from country to country, though in Britain the minimum acceptable number is generally seven. Research carried out in the USA suggests that the minimum acceptable number to ensure fairness is five foils plus the suspect (Wells et al., 1994). However, the actual number of foils on the parade is perhaps less important than their similarity to the suspect. As with photospreads, foils should only be included if their appearance is broadly similar to the description given by the witness. Any foils which can be immediately rejected (because their appearance does not match the description) may just as well not be there at all, as their rejection will be almost automatic. Brigham and Pfeiffer (1994) suggest that the fairness of a line-up should be judged not with reference to its actual size, but rather to its functional size. Thus an eight-person parade containing three foils which can be immediately rejected might be considered unfair while one which contains five appropriate foils may be considered fair, when in effect both sizes of parade are equally fair, as each have a functional size of five foils.
The choice of foils is thus crucial in determining the ease or difficulty of an identification procedure (Lindsay, 1994). The police may wish to increase the likelihood of a witness picking out the suspect by choosing foils who are significantly different from the suspect. By contrast, defence counsel might prefer to have foils whose resemblance is very similar to the suspect, thus making it less likely that the witness will be able to identify the suspect. In practice, the police now have lists of foils whom they can call upon to attend an ID parade. Such people’s physical appearance is kept on record so that in theory it should be possible to call only those whose physical appearance resembles that of a suspect. This is a considerable improvement on past procedures in which it was not unheard of for police officers who were about to go off duty to be called onto a parade to act as foils. In many cases, the physical appearance, stance and behaviour of the ‘foils’ made it very easy for any witness to spot the one person on the parade who stood out from the rest!
Even if the foils’ physical appearance is broadly similar to that of the suspect, it may still be possible for a witness to identify who the real suspect is on the parade by studying participants’ behaviour carefully. For example, it is feasible that the real suspect may be extremely nervous while the foils will be much more relaxed. Sweating, trembling or even subtler non-verbal behaviour may send a signal to the witness as to who the ‘real’ suspect is. While a guilty suspect may well be nervous, it might also be the case that a genuinely innocent person will also show signs of tension. While many humans may be quite adept at spotting when an individual appears to be experiencing stress, they may be less accurate in their presumptions about the factors underlying the tension. Although laboratory-based research studies examining identification procedures have been helpful in many areas, they are unable to replicate the tension which a real suspect on a real ID parade might experience. For this reason, it is not easy to call upon reliable research evidence to establish the extent to which wrongly accused suspects are likely to be picked out as guilty.
A further worry concerning ID parades is that, as with photospreads, the witness can look at the whole parade at once and make a decision on that basis. In theory, a witness’s task is to study each face in turn and to decide whether or not that face belongs to the person who they saw commit the crime. However, in practice, the witness may actually narrow down the possibilities by rejecting those which are the most dissimilar to their memory of the accused and eventually select the one whose appearance is most similar to the image in their memory (Thomson, 1995).
This latter problem could be eliminated if witnesses were prevented from seeing the whole parade at once. An alternative would be to have the witness simply view each face in turn and to say whether the face was or was not that of the accused. The witness would not necessarily be told in advance how many faces there would be on the parade, thus possibly making their decision more reliable. When such procedures have been used, they appear to be successful in reducing significantly the number of false positives which normal identification parades produce. (In this case a ‘false positive’ would be where a witness incorrectly identifies a face on the parade as that of the suspect.) Despite the demonstrated advantages of this method over traditional ID parades (Cutler and Penrod, 1995; Thomson, 1995), psychologists have to date been unsuccessful in persuading the authorities to adopt such procedures.
The 10-12 second 'rule'
A possible 'marker' or criterion for distinguishing between the good eyewitness testimony and the poor eyewitness testimony lies in the '10-12 second rule' (Dunning and Perretta, 2002). This is an idea derived from a great deal of evidence from experimental research on eyewitness psychology which has tended to find that eyewitnesses who identify someone from a line-up quickly tend to be more accurate than an eyewitness who takes rather more time. In other words, there is a negativerelationship between response latency and identification accuracy. One possible explanation of this is that the eyewitness who correctly identifies the offender needs to match the characteristics of each member of the line-up against the characteristics of the offender held in memory. This takes time but is relatively speedy because the major characteristics can be identified quickly - where the offender is not in the line-up the process takes longer since each line-up member has to be checked against the remembered characteristics. Similarly, if the memory of the characteristics of the offender is weak, then it takes a longer time to check these weak memories against the actual characteristics of people in the line-up. However, eyewitnesses who correctly fail to find a target in an identification parade (line-up) do not do this quicker than those who incorrectly decide that their target is not in the line-up. This makes sense in terms of the matching process just described since in both cases all of the checking process has to be gone through.
Weber et al. (2004b) studied the applicability of the 10-12 second rule using a number of data sets involving adults and children. A major finding is that the optimum delay differentiating accurate from inaccurate identifications was not constant and varied somewhat from the 10 seconds according to the age groups involved, for example. At best, they found a figure of 80% accuracy using the optimally differentiating time for any of their studies. They say that this makes the rule problematic for application in forensic settings. Indeed, they specifically suggest that the 10-12 second rule is an inadequate indicator of the accuracy of identification evidence (Weber et aI., 2004a). Nevertheless, the evidence did support the idea that decision speed was a good indicator of witness accuracy. The problem is that quite what decision speed is indicative of decision accuracy is tantalisingly variable and, as yet, not clearly identified with any particular aspects of research design. However, when a witness's confidence as well as their speed are both used in the assessment of accuracy, it became clear that accuracy of identification neared 90% for the confident witness who answered within the optimum time limit for accuracy.
Practices concerning line-ups or identification parades vary from country to country. The United Kingdom is particularly advanced in its thinking on these largely because of a record of wrongful convictions on the basis of identification evidence. In the 1970s, critical reviews of identification evidence were published including the influential Devlin Report. Other countries do not have quite the same procedural protection for suspects as the United Kingdom. Penrod (2003) argued on the basis of data from US line-tips that even cases where the guilty party is identified by the witness, that maybe as many of 20% of these are lucky guesses and not actual identifications as such. Furthermore, he estimates that as many as 50% of witnesses who made a choice were guessing. It is therefore important to note that Wells et al. (1998) proposed four general principles to protect the suspect. They are intended to guide the procedures used in line-ups/identification parades as well as photospreads. All of these seek to identify the offender. An analogy is drawn between a good line-up and a good psychological experiment:
. A properly designed experiment should be a fair test of the research hypothesis.
. A good experiment should be, as far is possible, free from biases.
Wells et al. suggest that two broad issues need to be taken into account:
. Structural properties, e.g. the appearance of the line-up in terms of how similar to and different from each other its members are.
. Procedural properties, e.g. the instructions given to the witnesses, the numbers in the line-up and so forth.
Consider some of the ideal characteristics of a study of human memory. The participants in the research listen to a list of words. They are then shown a sequence of words that may or may not have been in the original list. If the researcher testing their memory knows which words are in the original list then he or she may subtly and non-consciously give clues as to what these words were. For example, the researcher might pause fractionally longer over the critical words. There are indications that researchers are able inadvertently to bias an experimental outcome such that it favours the favoured hypothesis (Jung, 1971; Rosenthal, 1966). One way of reducing this influence is to keep the actual researcher in the dark about the hypothesis or leave them blind as to other aspects of the procedure (such as the list of words to be remembered). The rule for line-ups and photospreads is:
Rule 1: The person who conducts the line-up or photospread should not be aware of which member of the line-up or photospread is the suspect. (p. 17)
Even where the experimenter does not have knowledge about the list of words to be remembered, the participants may think that they do. Thus participants might inadvertently and wrongly read into the experimenter's behaviours what they believe to be cues about the correct words. For example, the experimenter might find certain words amusing and respond differently to these. Explaining to participants that the experimenter is unaware of what words are correct may reduce the effect.
Rule 2: The eyewitness should be told explicitly that the person administering the line-up does not know which person is the suspect in the case.
(p.19)The participant in the memory research might be inclined to pick out certain words simply because they are more interesting, more dramatic or in some way different. They may be inclined to pick these words as the correct ones as a consequence:
Rule 3: The suspect should not stand out in the line-up or photospread as being different from the distracters based on the eyewitness's previous description of the culprit or based on other factors that would draw extra attention to the suspect. (p. 19)
In the light of what we know about eyewitness confidence the recommendations also include the following:
Rule 4: A clear statement should be taken from the eyewitness at the time of the identification and prior to any feedback as to his or her confidence that the identified person is the actual culprit. (p. 23)
Kassin (1998) feels that there is an omission from these recommendations. He recommends that the identification parade/line-up and witness identification should be videotaped. This is because records of the line-up are often not carefully kept such that the police and eyewitnesses differ markedly in terms of their recollections of events at the line-up. He points out that police procedures in relation to evidence of various sorts have been subject to a variety of criticisms. For example, in the United Kingdom, the Police and Criminal Evidence Act of 1986 requires that all custodial interviews with crime suspects are taped. This, of course, is primarily to protect individuals against police malpractice. Relative judgement theory answers the question of how eyewitnesses choose the culprit from a line-up/identity parade. In the absence of the culprit, the theory suggests that the line-up members most similar to the culprit will be picked out. In other words, the eyewitness acts as if the culprit is present and forms a judgement on the best of what they recall of the culprit. No mechanism exists for deciding that the offender is not in the line-up (Wells, 1984). If participants were responding using absolute judgements, then each line-up member would be compared with the memory of the culprit. Then unless the line-up member meets the criteria they will be rejected. Evidence demonstrating the validity of relative judgement theory comes from studies such as that of Wells (1993). In this, some witnesses were shown the line-up including the culprit and others were shown exactly the same line-up with the culprit absent. Despite being told that the culprit may not be present, 54% of those who identified the culprit when the culprit was present would have identified someone else in the culprit's absence! When the offender was present, 21 % failed to make a choice but this increased to only 32 % when the culprit was actually absent. In other words, mostly when the offender is absent other, innocent, line-up members are chosen.
Obviously a major factor in this is that explicit warnings that the culprit may not necessarily be present substantially reduce wrongful identifications (Malpass and Devine, 1981). They do not affect rightful identifications when the culprit is present.
A number of studies have shown some of the factors that affect relative judgements in real cases. For example, Doob and Kirkenbaum (1973) reported on a Canadian robbery at a department store. The accused was said to be one of two men who had committed the crime. The cashier who witnessed the events recalled that the offenders were neatly dressed, good looking and could be brothers. Despite this somewhat sketchy recollection, she picked out the accused from a line-up. One of Doob and Kirshenbaum's studies had 20 women pick 'a rather good looking man' out of 12 parade participants from the original line-up. The women chose the accused extremely frequently despite not having witnessed the crime. This would appear to be evidence of the unfairness of the system employed.
Similarly, in Poland, Wojcikiewicz et al. (2000) were involved in a pertinent court case. The suspect was actually a man of 29 years of age. They were asked by the defence to assess how likely it was that a particular man, from the viewpoint of a 12year-old rape victim, could be described as being a 40-50-year-old man with a rat-like face. Adult participants in the research did see him as the 29-year-old that he was. However, about a fifth of the children saw the accused as being in the 40-45-year old age group. Adults described him as having a rat-like face although children did not have a significant tendency to do so. In view of this evidence, it remained possible that the accused was indeed the perpetrator. Nevertheless, the research evidence is indicative" of a possible problem and was used in court by the defence.
One way of assessing the likelihood that a person will be susceptible to relative similarity effects when choosing is their performance in the dual line-up. This involves an initial (or blank) line-up containing only people known to be innocent followed by a second line-up containing the suspect. Wells (1984) showed that:
. if a witness resists choosing from the blank line-up., it is more likely that they choose accurately in a proper line-up later;
. witnesses who did not go through the blank line-up first were more likely to make mistakes in the second line-up.
Sequential procedures also seem to work better than conventional line-ups. In these, the group of people selected to be in the line-up is shown in sequential fashion - one individual at a time. This makes it much more difficult simply to use a process of elimination in choosing the guilty party (it cannot be a, b or d so it must be c). It is less likely that relative similarity will operate in the sequential line-up (Dunning and Stern, 1994). Another identification method, very common in parts of the United States, is the show-up. This is a single individual which the eyewitness has to identify as the culprit or not. In one sense, this should be better in that a relative judgement cannot be made since there is only one person to decide about. On the other hand, the fact that the police have picked out this individual for the show-up may be strongly suggestive that they regard this individual as the prime suspect.
Steblay et at. (2003) carried out a meta-analysis of studies which compared the single-person line-up (the show-up) with six person line-ups (these included both sequential and simultaneous versions). Furthermore, both single-person show-ups and six person line-ups included conditions in which the target suspect was present in the majority of the studies. Interestingly, the line-up was much more likely to result in a choice by the eyewitness than the show-up. If the target were present, on average 71 % out of 10 line-ups resulted in a choice whereas the figure was only 46% for the show-up. Where the target was absent, 43 % of line-ups resulted in a choice as opposed to 15% of show-ups. Correct identification where the target was actually present did not differ between line-ups and show-ups. Around 46% correctly identified the suspect when the suspect was present in either type of identification procedure. Furthermore, when the target is absent, the false identification rate is approximately the same at about 16% for both show-ups and line-ups. What is happening when the eyewitness makes a wrong identification in a target absent line-up is that the errors are spread across all of the foils. This results in a situation in which if one classified all of these latter errors into a non-identification category with other non-identification outcomes, then line-ups show no difference from show-ups in terms of outcomes. It is important to note that those studies in which the foil is more similar to the target resulted in a worse performance in show-ups than in line-ups. False identifications of an innocent foil is more common in show-ups than in line-ups.
The procedures actually employed by police officers when they plan identification line-ups have been investigated by Wogalter, Malpass and McQuiston (in press). Over 200 police jurisdictions in the United States were surveyed about their practices. There were examples of good and bad practice as verified by laboratory studies. Some of the common good practices included:
.. Officers tended to choose line-up foils on the basis of upper facial features such as race/ethnic group, facial hair characteristics, colour of hair, and overall shape of face. Whatever the reason why the officers chose to do this, it is important to note that. there is a substantial amount of research evidence which suggests that people recall such upper facial features more readily than lower facial features (e.g. shape of the chin).
. Substantial numbers of officers report that they gave witnesses the option of not choosing anyone from the identification line-up though this is known to reduce errors as we saw above. However, very few warned eyewitnesses that facial features may change or that photographs may be of poor or insufficient quality. These factors may affect eyewitness accuracy according to research.
Examples of bad practice included:
. Most respondents (83%) claimed to base their choice of foils in the line-up on their similarity to the suspect. In contrast, only a small number (9%) based their choices of foil on the verbal descriptions provided by eyewitnesses. Research evidence has suggested that there may be problems with the use of similarity to the suspect as a criterion for choosing foils. This may seem to be a strange assertion given it would seem common sense to use identification line-ups of similar looking people. The problem is not in the theory but the practice. What actually happens is that the foils are chosen because of their similarity to the suspect rather than to each other. As a consequence, the suspect stands out because they have characteristics in common with many of the foils but the foils do not look too much like each other. In other words, there is a powerful clue in the situation which encourages the selection of the suspect.
. Generally, assessments about the fairness of the procedures being used by an officer are made by that officer (94%). They also might ask the advice of another officer (77%) or a prosecution lawyer (51 %). However, these are not completely independent judgements as they are all on the side of prosecuting the suspect. Asking the advice of the defence lawyer was fairly uncommon (only 15%) although this sort of advice might be regarded as a much more acid test of fairness.
. The use of video line-ups that do not require the direct recruitment of foils was relatively uncommon. But this is the sort of line-up that enables things like the editing out of any biasing behaviours on the part of members of the line-up.
We have already noted that perception can be influenced by prior beliefs and attitudes. Even support for different football clubs seems to affect perception, as Hastorf and Cantril (1954) demonstrated. They showed a film of a football game to fans from both sides and asked them to count instances of inappropriate behaviour and fouls. Guess the result? Each group of fans reported many more fouls from the opposing side.
Racial prejudice can very easily affect the way the world is viewed, as was vividly demonstrated by Duncan (1976) (see below). Chance and Goldstein (1996) have shown that identifying faces from a different ethnic group is more difficult than identifying faces from one’s own group, because of inappropriate and unfamiliar encoding strategies. The area of cross-race identification thus produces a particularly problematic issue in evaluating eyewitness testimony.
The difficulties in cognitive processing faces of a different race are compounded by stereotypical attitudes held about the race. Duncan (1976) was interested in the effect of stereotypes on perception. White participants were asked to view a video of a disagreement between two people which resulted in one pushing the other. In fact four versions of the video were shown to different groups:
Tape 1 (White assailant/white victim)
Tape 2 (White assailant/black victim)
Tape 3 (Black assailant/white victim)
Tape 4 (Black assailant/black victim)
Participants were asked whether the behaviour of the person who pushed the other could best be described as ‘playing around’ or as violent behaviour. When the perpetrator was black, 70% of participants described his behaviour as violent, while only 13% of participants chose this descriptor when the perpetrator was white. The attribution of violence was highest for Tape 3, and lowest for Tape 1.
Peter B. Ainsworth, 2000, Psychology and Crime, Longman, 0-582-41424-5
Kevin Brewer, 2000, Psychology and Crime, Heinemann, 0-435-80653-X
Diana Dwyer, 2001, Angles on Criminal Psychology, Nelson Thornes, 0-7487-5977-8
Julie Harrower, 2001, Psychology in Practice – Crime, Hodder & Stoughton, 0-340-84497-3
Dennis Howitt (2006) Forensic and Criminal Psychology, Pearson Prentice Hall, ISBN 0-13-129758-9