There are several ways a crime victim or other eyewitness might have an opportunity to identify a stranger-perpetrator of a crime before being called as a witness in court. (If the perpetrator is an acquaintance, the ID will not generally be an issue.)
• Public Confrontation. The witness might chance to see the perpetrator someplace around the neighborhood or in the community, such as while shopping or attending an event.
• Field Showup. Police detain a suspect near the scene of a recently committed crime and seek an ID or elimination from the victim or witness, who might be brought to the suspect's location for a viewing.
• Photo Display. An array of several pictures or a sequence of pictures of suspects and "fillers" who resemble the description may be presented to the witness.
• Stationhouse Showup. The witness is asked to look at the suspect in the police station and indicate whether or not the person is recognized.
• Lineup. The suspect and a number of similar "fillers" may be displayed together, or sequentially, usually at the police station or jail.
• Courthouse Confrontation. Before the court hearing or trial, the witness sees and recognizes the perpetrator in or around the courthouse.
Except for the confrontations (which are chance encounters not arranged by law enforcement officers), these procedures must be conducted in a non-suggestive manner that meets due process requirements of reliability. The U.S. Supreme Court has also issued several opinions discussing the applicability of the Sixth Amendment right to counsel to certain pretrial ID processes.
U.S. v. Wade
After Billy Joe Wade was indicted and had counsel appointed on a federal bank robbery charge, agents brought two witnesses to a lineup and sought IDs. Both witnesses identified Wade as one of the robbers, and he was convicted at trial. The Supreme Court reversed, ruling that Wade's constitutional right to counsel had attached by indictment, and the lineup after that point was a "critical stage" of the case at which counsel should have been present:
"Since the presence of counsel can often avert prejudice and assure a meaningful confrontation at trial, there can be little doubt that the postindictment lineup was a critical stage of the prosecution at which [the defendant] was as much entitled to aid of counsel as at the trial itself. Thus, both Wade and his counsel should have been notified of the impending lineup, and counsel's presence should have been a requisite to conduct of the lineup, absent an intelligent waiver."
Gilbert v. California
The companion case to Wade also ruled that ID evidence from a lineup held without counsel, after indictment and arraignment, was inadmissible at trial. Further, since the pretrial ID was improperly conducted, the in-court ID would also have to be excluded, unless the trial court found that the courtroom ID was sufficiently independent of the pretrial ID as to be disassociated from the impropriety:
"Police conduct of [a postindictment pretrial] lineup without notice to and in the absence of counsel denies the accused his Sixth Amendment right to counsel and calls in question the admissibility at trial of the in-court identifications of the accused by witnesses who attended the lineup."
The rule requiring counsel for a lineup staged after indictment or arraignment is known as the "Wade-Gilbert Rule." But would this rule also apply to a lineup or showup that takes place before the suspect has been formally charged, or before he or she has made the first court appearance on the case? That question was answered in a case from Illinois.