Handbook of Psychology of Investigative Interviewing: Current Developments and Future Directions
Page 44
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Klavehn, 2000 for a review). Applying this theoretical framework to eyewitness
identifi cation suggests that it may be benefi cial in future research to explore
use of instructions to witnesses that encourage a recollection judgement and
discourages identifi cation based on a feeling of familiarity.
Factors that a ffect e yewitness i dentifi cation
Crime scene investigators take great care to avoid contaminating a crime scene
by introducing new trace evidence. The memory of an eyewitness should be
treated similarly, as part of the crime scene. Investigating offi cers should take
care to ensure that they do not distort a witness ’ s memory, but instead use a
sensitive and fair procedure to obtain identifi cation evidence of the highest
quality. An investigating offi cer has control over many aspects of an eyewit-
ness ’ s interaction with the investigation. For example, an investigator may
develop a strategy to interview a witness, decide which witnesses will be asked
to make an identifi cation, selecting an appropriate method, brief the witness
and control the information provided to the witness after an identifi cation
procedure.
The selection and design of identifi cation procedures can have a strong
impact on the reliability of the eyewitness evidence obtained. A poorly designed
procedure might distort a witness ’ s memory, potentially leading to a mistaken
identifi cation of an innocent suspect or a missed opportunity to collect
Recent Developments in Eyewitness Identifi cation Procedures
227
identifi cation evidence against a guilty suspect. Psychological science can
eva luate identifi cation procedures. For example, the selection of foils for a
line - up, the instructions given to witnesses and prior viewing of photographs
have all been shown to have a marked effect on the reliability of eyewitness
identifi cation.
Selection of f oils
The PACE code of practice specifi es that the foils for line - ups must be selected
to ‘ resemble the suspect ’ . This is known as a suspect - resemblance strategy.
Luus & Wells (1991) argued that a better strategy is to select foils who match
the witness ’ s description of the culprit. It is reasonable to assume that the
witness can remember the description that he or she gave to the police and
may expect to identify somebody who matches their description. Therefore,
the witness may be inclined to disregard any foils that do not match their
description, or conversely pay special attention to anybody who is a better
match to their description than the rest. Luus & Wells suggested that it does
not introduce a bias against an innocent suspect if line - up members differ on
a feature that was not mentioned in the original description. Differences in
the facial features of line - up members will help a witness who has a reliable
memory to distinguish the culprit from the foils. If the suspect is not the
culprit, he or she is no more likely than anybody else to be mistakenly identi-
fi ed by a feature not mentioned in the description because the witness has not
seen the suspect before. All persons in a fair line - up should match the witness ’ s
description of the culprit.
Sometimes a witness may not mention the sex or race of a person, or may
neglect to say that somebody did not have a beard or was not wearing glasses.
This may occur because the witness assumes a default value (Lindsay, Martin
& Webber, 1994 ). When constructing a culprit - description line - up, account
must be taken of default values. Alternatively, if a witness ’ s description is very
vague or if the suspect does not match the description, it may be necessary to
resort to a suspect - resemblance strategy. The important principle is that the
suspect should not stand out in the line - up.
Different foils may be required for a culprit
- description line
- up for
each witness, because their descriptions of the culprit may differ. Therefore,
use of culprit - description line - ups would require additional police resources.
In the UK current practice requires only a single line - up to be used for all
witnesses, although the position of the suspect may differ across different
witnesses.
Empirical support for the superiority of a culprit
- description line
- up is
mixed. Wells, Rydell & Seelau (1993) and Juslin, Olsson & Winman (1996)
reported more correct identifi cations from culprit - description line - ups than
from suspect - resemblance line - ups when the culprit was present in the line - up,
and no signifi cant difference in the number of mistaken identifi cations from
culprit - absent line - ups. In contrast, Lindsay et al. (1994) , and Tunnicliffe &
228
Handbook of Psychology of Investigative Interviewing
Clark (2000) did not fi nd any statistically signifi cant advantage for culprit -
description line
- ups over suspect
- resemblance line
- ups. Use of culprit
-
description line - ups in the context of video identifi cation is discussed below.
Instructions to w itnesses
A witness may believe that they have been invited to attempt an identifi cation
because the police have good reason to believe that the suspect is guilty.
Therefore, a witness may assume that it will help the police if they identify the
suspect. It is important that the instructions to the witness should emphasize
the possibility that the offender may not be in the line - up. The PACE code
of practice includes the instruction that the person whom the witness saw ‘ may
or may not be present ’ . Furthermore, the witness must be instructed that ‘ If
you cannot make a positive identifi cation, you should say so ’ . Instructions that
do not point out that the culprit may not be in the line - up are regarded as
‘ biased ’ (e.g., ‘ Can you identify the man who assaulted you? ’ ). A meta - analysis
of 18 studies showed that when biased instructions are given, witnesses are
more likely to make an identifi cation, whether it is correct or incorrect. Biased
instructions increase the likelihood of an innocent suspect being identifi ed
from culprit - absent line - ups (Steblay, 1997 ).
Blind a dministration of l ine - u ps
‘ Blind ’ is used in the sense that the line - up administer does not know (i.e. is
blind to) the identity of the suspect. The procedure is often referred to as
‘ double - blind ’ , meaning that both the witness and the line - up administrator
are blind to the identity of the suspect. A double - blind procedure should be
used to prevent any inadvertent infl uence on the witness. Such infl uence can
be very subtle and entirely unconscious. For example, the administrator may
look at the witness when the suspect ’ s image is being viewed, or be more likely
to accept a tentative identifi cation only if it is of the suspect. Currently, the
PACE code of practice does not require double - blind administration.
There is little direct evidence on the double - blind administration of line -
ups. However, the effects of experimenter - induced i
nfl uence are well estab-
lished in a broader context in psychological science (Harris
& Rosenthal,
1985 ). For this reason a double - blind procedure is an essential feature of clini-
cal drug trials. The essential point to appreciate is that double - blind adminis-
tration of identifi cation procedures removes any possibility of that the witness
may have been infl uenced. Therefore, double - blind administration protects the
police from malicious accusation of bias and enhances the perceived integrity
of the identifi cation evidence. Widespread use of photographs for identifi cation
in the USA and of video in the UK greatly facilitates use of a double - blind
identifi cation procedure.
Recent Developments in Eyewitness Identifi cation Procedures
229
Number of f oils
Video or live line - ups in England and Wales are required to have a minimum
of eight foils. It is recommended by the US Department of Justice that photo
line - ups have a minimum of fi ve foils and live line - ups have a minimum of four
foils (Technical Working Group on Eyewitness Identifi cation, 1999 ). These
guidelines raise the question of how many foils is optimal.
The similarity of foils to the culprit is more important than the abso-
lute number of line
- up members. A foil who is dissimilar to the culprit
will be discounted by the witness. The ability to identify a target face
from target - present and target - absent photo line - ups decreases with increa-
sing size of the line - up (Meissner et al. , 2005 ). Thus the target person is
most likely to be identifi ed from a one - person line - up (a show - up or con-
frontation) and least likely to be identifi ed from a 12
- person line
- up.
This result is unsurprising because a line
- up that offers more alternative
responses provides a more diffi cult test of memory. It is only an identifi ca-
tion of an innocent suspect that is a forensically relevant mistaken identifi cation
(i.e., likely to lead to a miscarriage of justice). In a one - person target - absent
line - up all mistaken identifi cations will be of the innocent suspect. Fewer
mistaken identifi cations are likely to be of an innocent suspect in a large
target - absent line - up than in a small line - up. In summary, there is no clear
empirical guide to the optimal size of a line - up, but if foils are appropriately
chosen, a larger line - up is likely to pose a more challenging assessment of
eyewitness memory.
Prior e xposure to p hotographs
If the police have not identifi ed a suspect, the witness may be shown photo-
graphs of people associated with similar offences (mugshots). This procedure
differs from a line - up in that all the people are potential suspects. Therefore,
any identifi cation will lead to that person being investigated. Later in the
investigation the police may want to collect formal identifi cation evidence from
a line - up, or may be required to do so by legislation. Would a subsequent
line - up be biased against the suspect if the witness has previously seen their
photograph in a mugshot album?
Deffenbacher, Bornstein
& Penrod
(2006) provide a systematic review
of the effects of mugshot exposure. They found that prior viewing of a pho-
tograph of somebody who subsequently appeared in a line
- up increased
the probability of a mistaken identifi cation from the line - up. This effect is
due to transference of familiarity from the photograph which is mistakenly
attributed to having being seen at the crime scene. The effect is stronger when
few mugshots were viewed (8 – 15 or fewer) than when more mugshots have
been viewed. The effect is particularly strong if the person was mistakenly
identifi ed as the perpetrator from the mugshot photographs. This is known as
230
Handbook of Psychology of Investigative Interviewing
an effect of commitment to the earlier identifi cation. There was no ill - effect
of showing photographs if none of the people seen appeared in the subsequent
line - up.
Video i dentifi cation and i ts a dvantages
Since 2003 video technology has been used to replace virtually all live identity
parades in England and Wales. A video line - up consists of 15 - second clips
showing the head and shoulders of each line
- up member. First, they are
looking at the camera and then rotate their head to show both profi les, before
looking back at the camera. The images are captured under standardized con-
ditions. Each line - up member is shown sequentially, with a digit in the top
left corner of the screen to identify each individual.
Video offers a number of benefi ts compared to live line - ups:
1. Video can dramatically reduce the delay before an identifi cation can be
organized. A video line - up can be produced and transmitted via a secure
network within two hours of request.
2. The administration of the video identifi cation procedure can be arranged
at the convenience of the witness rather than at the convenience of
the suspect, because the suspect does not attend the video identifi ca tion
procedure. This results in fewer identifi
cation procedures being
cancelled.
3. A large database of video clips (in excess of 20,000) is available, providing
more foils for selection. This makes it easier to select foils that resemble
the suspect in appearance.
4. Video is less threatening to victims, who no longer have to attend an
identifi cation suite where, for example, their attacker may be physically
present.
5. Video equipment can be taken to a witness who is unable to attend the
police station. For example, a victim of a violent attack may be able to
view a video line - up from a hospital bed or a witness could view a line - up
anywhere in the world.
6. The suspect no longer has the opportunity to change their appearance if
their image was captured for the video identifi cation when they were fi rst
detained.
7. A video line
- up does not require the continuing co
- operation of the
suspect. Once the suspect ’ s image has been captured for a video line -
up, the suspect
’ s co
- operation with the procedure is no longer
required.
Video identifi cation has had a considerable impact on the investigative
process due to development of legislation and technology. In certain instances
when there is a suspect known to the police but who is unavailable, identifi ca-
Recent Developments in Eyewitness Identifi cation Procedures
231
tion offi cers may hold an identifi cation procedure in advance of any arrest using
any suitable still or moving image of the suspect. This same principle of using
historically held imagery may be applied to a person suspected of committing
a crime many years ago and whose appearance has changed ( R v Folan , 2003 ).
Forensic advances in the use of DNA evidence and an ever - increasing database
of suspect images means that this aspect o
f crime investigation is set to increase.
Overall, the speed of process that video identifi cation provides has, in many
instances, hastened the outcome of an investigation where identifi cation is
deemed an issue. It is not unusual, particularly where serious crime is involved,
for the identifi cation procedure to be conducted whilst the suspect is in
custody. A further feature of video technology is the ability to cover or replicate
distinguishing features on the faces of the suspect and/or the foils (e.g. scars,
tattoos etc.) to ensure a procedure complies with legislation. This issue is
discussed in more detail below.
The i ncreased u se of e yewitness i dentifi cation e vidence
Devlin (1976) ascertained that 2,116 identity parades were held in England
and Wales during 1973. PACE resulted in an increase in the use of identity
parades, because it gave suspects the right to an identity parade if identifi cation
is disputed. Slater
(1994) reported data from 24 of 52 UK police forces
showing a sharp rise in the number of identity parades organized during the
period 1990 – 93. In 1993 the 24 police forces who reported data organized
13,652 identity parades. The introduction of video together with further leg-
islative changes, which has made it easier to organize identifi cation procedures,
has resulted in a further sharp increase in demand. The best estimate for 2006
suggests that the number of video identifi cation procedures had reached a
minimum of 80,000 annually. Paradoxically, the courts now rely more on
eyewitness identifi cation than they did in the 1970s when Devlin analysed
eyewitness identifi cation evidence.
Research on v ideo i dentifi cation
The format of presenting a line - up (photographs, video, live) and manipulation
of the richness of cues available (e.g. stills, moving images, people walking)
has a surprisingly small effect on identifi cation accuracy. A possible reason is
that the face is the most reliable way to recognize somebody and the face can
be suffi ciently well perceived from a good quality still photograph. Therefore,
relying on cues such as gait, build or colour images would add little extra
benefi t. Reviewing the literature, Cutler, Berman, Penrod & Fisher concluded:
‘ With respect to current practices, the conservative conclusion is that, based
on available research, there is no reason to believe that live line - ups, videotaped