Discuss the importance of pre-lineup instructions for identification procedures using lineups

Question

What will be an ideal response?

Answer 1

Suggestion is particularly powerful, and most threatening to accuracy, after a crime has been committed. Suggestions that come from others add to what a witness believes they observed during the crime. These added "facts" are then mentally stored in a witness's memory. When the witness later is asked to recall the event at trial, the witness testifies about these suggested facts as if they were things the witness had actually observed.

Witnesses think of live lineups and photo lineups as multiple choice tests without a "none of the above" choice. They think of show-ups and single pictures as true or false tests. Witnesses thus feel like they have to choose the "best likeness" in a lineup, but give a "true" or "false" response in the show-ups. Witnesses feel pressured by the possibility that they might look foolish if they "don't know the answer.".

The very fact that police have arranged an identification procedure also puts pressure on witnesses. They believe the police must have found the culprit, or they wouldn't have gone through the trouble of arranging such a procedure. So witnesses often tell themselves the culprit has to be there and feel pressured to identify somebody.

Much of the psychological research into eyewitness identifications suggests that officials should use the may-or-may-not-be present instruction—the person administering the procedure tells a witness before they view the lineup that the suspect may or may not be present. The research shows that if this instruction is not given, misidentifications are more likely than if it is given. Administrators can bias the lineup identification even more by telling a witness that police have already found the perpetrator, that police know who the perpetrator is, or that police have plenty of evidence against the perpetrator.

Administrators can also give witnesses other verbal and nonverbal cues that may not be intentional or even done consciously.