Police lineups
Police lineups are investigative tools used by law enforcement to identify suspects based on eyewitness testimony, which is often considered a vital element in solving crimes. There are three primary forms of lineups: photographic lineups, traditional lineups with suspects and look-alikes, and showups, where a single suspect is presented to a witness. These procedures must adhere to constitutional rights to avoid violating the due process of suspects. Notably, a suspect is entitled to counsel during a lineup if it occurs after criminal proceedings have begun, but not before. The reliability of eyewitness identification can be compromised, leading to the risk of misidentification. Factors influencing this risk include the witness’s opportunity to observe the suspect and their certainty during identification. To mitigate misidentification, practices like double-blind lineups, where the officer does not know the suspect's identity, and sequential lineups, where suspects are shown one at a time, have gained traction. These methods reflect an evolving understanding of the complexities surrounding eyewitness testimony and its implications in the justice system.
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Police lineups
SIGNIFICANCE: Police lineups may be useful tools in police investigations, but if performed improperly they violate suspects’ rights and lead to false identifications by witnesses.
Police investigators use lineups as an analytical tool based on the premise that eyewitness testimony is the strongest evidence to use in the investigation of crime. The purpose of police lineups is to check the veracity of eyewitness statements for the purpose of identifying a suspect.
There are essentially three forms of police lineups. The photographic lineup can be done exclusively with the use of photographs (or “mug shots”) in which a photograph of the suspect can be placed within an array of other photographs. A more common form of lineup is to have a suspect stand in a room with other people, known as foils, who look similar. Sometimes a lineup consists only of foils. Police may also make use of showups, in which one suspect appears before a victim or witness. Some investigators prefer to use a combination of these techniques, such as first requesting a photographic lineup and then later a regular police lineup or showup.
Investigators are bound by constitutional requirements concerning the use of lineups. As in all other investigative procedures, police cannot violate the suspect’s due process rights; thus, in some cases the accused must be provided with counsel during the lineup procedure. The U.S. Supreme Court ruled in Kirby v. Illinois (1972) that a person at a lineup or showup has a right to counsel if the investigative procedure is held at or after the time that criminal proceedings have begun. However, if the lineup is conducted before the beginning of criminal proceedings, a suspect is not entitled to counsel. Counsel is also not required for photographic lineups. A defendant may request a waiver of rights to have counsel at a lineup or showup provided that the defendant is made aware of the procedure and the fact that the purpose of the procedure is for the identification of a criminal suspect.
The Problem of Misidentification
The issue of the possibility of misidentifications in police lineup procedures has been debated both by the Court and by scholars. In Neil v. Biggers (1972), the Court opined that five factors should be used to detect misidentification. The factors include the opportunity of the witness to view the criminal at the time of the crime, the witness’s degree of attention, the accuracy of the witness’s prior description of the criminal, the level of certainty demonstrated by the witness at the confrontation, and the length of time between the crime and the confrontation.
Further, scholars suggest that misidentification could be reduced by using either double-blind police lineups or sequential lineups. The double-blind procedure is based on a premise posited by several scholars that police officers who know the identity of the suspect may influence the decision of the eyewitness. The double-blind procedure thus prevents this by having the supervising police officer of a lineup unaware of who the possible suspect is. Sequential lineups require that eyewitnesses view potential suspects one at a time, rather than all at once. The sequential lineup procedure is based on the belief that eyewitnesses may be prone to make relative judgments and thus choose a suspect who looks most like the perpetrator when all of the suspects are viewed at once. Many police departments have begun utilizing both of these procedures in recent years.
Bibliography
Loftus, Elizabeth F. Eyewitness Testimony. Cambridge, Mass.: Harvard University Press, 1979.
Meyer, Marlene, et al. "Enabling Witnesses to Actively Explore Faces and Reinstate Study-test Pose During a Lineup Increases Discriminability." Proceedings of the National Academy of Sciences (PNAS), vol. 120, no. 41, 2 July 2023, doi.org/10.1073/pnas.2301845120. Accessed 9 July 2024.
Sharps, Matthew J. "Protecting the Innocent: Lineups, Good and Bad." Psychology Today, 13 Feb. 2023, www.psychologytoday.com/us/blog/the-forensic-view/202301/protecting-the-innocent-lineups-good-and-bad. Accessed 9 July 2024.
Technical Working Group for Eyewitness Evidence. Eyewitness Evidence: A Guide for Law Enforcement. Washington, D.C.: U.S. Department of Justice, Office of Justice Programs, National Institute of Justice, 1999.