Police lineup

A police lineup (in American English) or identity parade (in British English) is a process by which a crime victim or witness's putative identification of a suspect is confirmed to a level that can count as evidence at trial.

The suspect, along with several other individuals (called "fillers" or "foils") of similar height, complexion and build (these can be prisoners, actors or volunteers) stand both facing and in profile. This is sometimes done in a special room which includes details like a height measurement grade on the wall to aid identifying the person's height. The person making the identification views from behind a one-way mirror or similar protection to guarantee the suspect identified by the witness cannot know the identity of the witness.

Alternatively, photographs of the suspect and fillers can be shown to the identifier in what is called a "photo-lineup", or a "six pack" . If the victim or witness successfully identifies the suspect from among the fillers, the identification is considered valid. There is some research into using other methods of photo-lineup that involve the witness sequentially viewing photographs rather than simultaneously.

For evidence from a lineup to be admissible in court, the lineup itself must be conducted fairly. The police may not say or do anything that persuades the witness to identify the suspect that they prefer. This includes loading the lineup with people who look very dissimilar to the suspect.