The Matrix defense is the term applied to several legal cases of a defense based on the Matrix films where reality is actually a computer generation—simulism—and that the real world is quite different from what reality is perceived to be.In using this defense, the defendant claims that he committed a crime because he believed he was in the Matrix, and not in the real world. This is a version of the insanity defense and considered a descendant of the Taxi Driver defense of John Hinckley, one of the first defenses based on blurring reality with the movies. Regardless of whether the defendant actually believes that he or she was living inside the Matrix, this defense has been used successfully to put users inside of mental-care facilities instead of prisons: Tonda Lynn Ansley of Hamilton, Ohio, was found not guilty by reason of insanity using this defense after shooting her landlady in the head in July 2002.
Vadim Mieseges of San Francisco offered a "Matrix" explanation to police after chopping up his landlady, and was declared mentally incompetent to stand trial.
Joshua Cooke's lawyers were going to attempt this defense in 2003 in his trial for the murder of his adoptive parents, before he pleaded guilty.
The case of Lee Malvo also included references to The Matrix, mentioned in the writings taken from his jail cell; he reportedly shouted "Free yourself from the Matrix" from his cell after his arrest, and told FBI agents to watch the film if they wanted to understand him.