Lineups

Nearly everyone is familiar with the standard American lineup: six individuals (the suspect plus five “foils” or fillers), all of whom are shown (often standing in front of a height chart) to the witness, who views the lineup members from behind a one-way mirror; is given an opportunity to observe each member of the lineup; and is instructed to make an identification, if possible, or reject the lineup. The police officer who assembled the lineup has selected foils who resemble the suspect (often using other police officers or people who are in custody), arranged the presentation (sometimes in consultation with the suspect's defense attorney), and presented the lineup to the witness—sometimes with an admonition that the witness should take his or her time.

The standard lineup has come under intense criticism from the scientific community for two reasons: (a) It is increasingly evident that many erroneous convictions arise from misidentifications of innocent suspects; and (b) many scientific studies have compared the performance of witnesses in the standard lineup versus alternative procedures, and the standard procedures prove inferior in a number of ways. Improved procedures have been recommended by a number of sources, including a [Page 275]set of recommendations compiled in 1999 by the Department of Justice:

Use larger lineups. One objective in conducting lineups is to maximize the ratio of correct to incorrect suspect identifications. Incorrect suspect identifications (made by witnesses who guess incorrectly) can, at worst, lead to erroneous convictions and can, at best, waste the time of the police, who may continue to collect evidence against an innocent person while the guilty person remains on the street and the trail of evidence grows cold. Arrays of nine, as used in Britain, would spread identifications by witnesses who are merely guessing across a larger number of known-innocent foils—in fair lineups, the suspect would be guessed in one in nine instances rather than one in six. Experimental and archival studies indicate that witnesses are highly prone to guessing—about 25% of witnesses choose foils even when a perpetrator is present in a lineup or photo-array (and, of course, logic and these numbers dictate that some of the witnesses who identified the suspect/perpetrator merely guessed correctly), and 50% will guess a foil when the perpetrator is not present.

Use blind presentation. The person who conducts the lineup or photo spread should not be aware of which member of the lineup or photo spread is the suspect. The rationale is that blind presentation will eliminate the possibility that police officers administering lineups can intentionally or unintentionally communicate information to a witness about which lineup member is the suspect.

Give strong cautionary instructions. Eyewitnesses should be told explicitly that the perpetrator might not be in the lineup, and they should not feel that they must make identification. Witnesses should also be told that the person administering the lineup does not know which person is the suspect. Cautionary instructions have been shown to reduce guessing by witnesses.

Match foils to the description of the perpetrator. The suspect should not stand out in the lineup or photo spread as being different from the foils, based on the eyewitness's description of the perpetrator or other factors that would draw extra attention to the suspect. Foils generally should not be selected to look like the suspect, but instead should fit the description the eyewitness made of the perpetrator. Such selection strategies can reduce biases against suspects. Description-matched lineups have been shown to produce substantially fairer lineups.

...