Eyewitness lineups: is the appearance-change instruction a good idea?

Area of Science:

• Psychology
• Forensic Science
• Eyewitness Testimony

Background:

• The Department of Justice's Guide for lineups suggests warning eyewitnesses about potential culprit appearance changes.
• This appearance-change instruction (ACI) has not been empirically validated.

Purpose of the Study:

• To empirically test the effectiveness of the appearance-change instruction (ACI) in eyewitness identification procedures.
• To determine if the ACI impacts identification accuracy, false alarms, and witness confidence.

Main Methods:

• 289 participants viewed a crime video and identified culprits from 6-person lineups.
• Participants either received the ACI or not, with warnings that the culprit might be absent.
• Culprit appearance changes varied between the crime video and lineup arrays.

Main Results:

• The ACI did not improve culprit identification accuracy across varying degrees of appearance change.
• The ACI increased false alarms and filler identifications while decreasing witness confidence.
• Response latency increased with the ACI, suggesting a more cautious, yet less accurate, identification process.

Conclusions:

• The appearance-change instruction (ACI) may negatively impact eyewitness identification accuracy.
• Potential mechanisms include decision criterion shifts and increased ecphoric similarity.
• Current recommendations for the ACI in lineup procedures may require re-evaluation based on empirical evidence.