A more thorough explanation:

A pretrial lineup is a procedure used by law enforcement officers to identify a suspect in a crime. It involves placing the suspect in a line with other individuals and presenting them to a witness or victim who is asked to identify the perpetrator.

For example, if a witness saw a person commit a robbery, the police may conduct a pretrial lineup with several individuals who match the witness's description of the suspect. The witness would then be asked to identify the person they saw commit the crime.

Pretrial lineups are often used in criminal investigations to help identify suspects. However, they can be controversial because they rely on the accuracy of eyewitness testimony, which can be influenced by factors such as stress, fear, and memory distortion.