Eyewitness Identification: Experimental Data, 2016-2019

Fitzgerald, Ryan (2021). Eyewitness Identification: Experimental Data, 2016-2019. [Data Collection]. Colchester, Essex: UK Data Service. 10.5255/UKDA-SN-854733

After observing a crime, eyewitnesses can provide law enforcement personnel with important information about the criminal's identity. This is often achieved by pointing out the criminal from an identity parade. The basic procedure for an identity parade is to have the witness inspect a group of people and judge whether one of them is the criminal, but the procedures used to administer identity parades vary substantially across jurisdictions. In countries like Australia and South Africa, parade members appear in person - similar to how identification procedures tend to be depicted in popular films. Live parades are also used in the USA and Canada, but identification from photographs (or "mugshots") is far more common. In the UK, recent legislation has led to the widespread use of video technology to present identity parades. Such disparity in procedures begs the question: Which one is best?

When considering the pragmatics of the different techniques, photo and video identifications are the clear favourites. Finding suitable people to appear in a live parade is not always easy, whereas the availability of large databases of photo and video images make these alternative forms of identity parades substantially more manageable to construct. Video and photo parades are also less expensive than live parades because the parade members do not need to be paid each time they appear.

Although the practical benefits of photo and video parades are clear, eyewitness scientists have yet to reach a consensus on which procedure is most likely to facilitate a correct identification decision. This is a huge societal problem because if a witness is unable to identify the criminal, investigators may not have the evidence required to secure a conviction and hold the criminal responsible. There is also a very real possibility that an eyewitness will mistakenly identify an innocent person. When this happens, the innocent person is at an increased risk of wrongful conviction. Wrongful convictions happen quite frequently and in a review of convictions that were proven to be wrongful in light of DNA evidence, mistaken identifications were present in over 70% of the cases and was the leading contributing factor (www.innocenceproject.org).

Sometimes false identifications are beyond the justice system's control, but decades of scientific research have demonstrated that eyewitness identification policies and procedures can have a significant impact on the reliability of eyewitness identifications. This is why it is crucial to know how identifications are affected by presenting the identity parade members in person, on video, or with photographs. One thing to consider is that live procedures give witnesses the opportunity to see the parade members in their entirety, whereas photo and video procedures typically only provide a head-and-shoulders view. All else equal, the ability to see the parade members from top to bottom should improve eyewitness identification performance. In practice, however, the logistical constraints of live identifications might wipe out any of these theoretical benefits.

The proposed research will provide a rigorous comparison of live, video, and photo parades, and it will also introduce a novel procedure that shows videos of the entire person. The novel procedure has been designed to retain the practical advantages of video parades, but also provide witnesses with the additional memory cues that are available for live parades. The people who are investigating crimes and setting eyewitness identification policy are currently facing a paradox: the most practical identification procedure may not produce the best identification outcomes. When the proposed research has been completed, the data will inform investigators and policy-makers on which identity parade modality produces the best identification outcomes.

Data description (abstract)

Eyewitnesses are widely believed to have a better chance of identifying a perpetrator from a live identification procedure than from photo or video alternatives. To test this live superiority hypothesis, prospective students and their parents (N = 1048) became unsuspecting witnesses to staged events and were randomly assigned to live, photo, or video identification procedures. In Experiment 1, participants viewed a single person at the identification procedure. In Experiment 2, participants viewed a lineup of six people. Across experiments, live identification procedures did not improve eyewitness identification performance. The results show that even under experimental settings designed to eliminate the disadvantages of conducting live lineups in practice, live presentation confers no benefit to eyewitnesses.

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