An alibi, in its most basic form, is a plea that one was not present when a crime was being committed. In practice, alibis can be considerably more complex than a simple narrative story. In the criminal justice system, alibis function as exculpatory evidence—a good alibi should rule out the alibi provider as a potential suspect in a case or provide reasonable doubt as to a defendant's guilt in a criminal trial. Psychological research into the study of alibis is a relatively new area in psychology and law. This entry summarizes some of the major findings and introduces the terminology of the existing psychological literature.

It is unclear how alibis are used in the early stages of criminal investigations, and the rules about how and when ...