When Tonda Lynn Ansley confessed to shooting her landlord on a crowded street, she cited the movie "The Matrix" as evidence the killing was "morally right."
Ms. Ansley, who was found not guilty by reason of insanity last month, told homicide detectives in Hamilton, Ohio, she was living in "The Matrix," a violent movie in which "they commit a lot of crimes" and "you think it's a bad dream."
Ansley is not the only defendant to invoke a movie as defense in court. Whether as inspiration or evidence of insanity, movies have been cited by suspects as diverse as John Hinckley, Jr., who said he tried to assassinate President Reagan after watching "Taxi Driver," to accused sniper Lee Malvo, who cited "The Matrix" in his statement to police. In civil lawsuits, victims have argued that such movies inspired copycat crimes.
Studies suggest as many as one-quarter of juveniles involved in criminal cases now cite films, video games, or songs to explain their crimes, says Jacqueline Helfgott, a Seattle University criminal justice professor. "Our culture has become so media-saturated," she says. "I would expect it to come up more and more."
The contexts in which movies pop up in cases vary. Detectives may mention a suspect's favorite movies as a way to get him talking during an interrogation. "You know that will strike a responsive chord," says John Kunich, a law professor at Roger Williams University in Bristol, R.I.
At trial, both prosecutors and defense attorneys use the common language of films to frame cases for jurors.
But experts could cite no examples where defendants had successfully persuaded courts that movies excused their own criminal behavior.
At least a dozen murders have been linked to people who watched "Natural Born Killers," a 1994 film directed by Oliver Stone. None convinced a court that the movie made them do it.
Movies are more useful in insanity defenses, as evidence that a defendant is detached from reality. "When lawyers present an insanity defense, they look very hard for everyday ways of showing jurors the degree of the defendant's disorder," says David Siegel, a professor at the New England School of Law in Boston.
In most cases, a movie is just one of many pieces of evidence. That was true in the case of Ansley, whom three psychologists found too mentally ill to be held responsible for shooting her landlord.
"A rational soul doesn't allow a movie to order them or suggest to them that they could kill somebody," says Craig Hedric, the prosecutor who led the case.
In civil lawsuits, Kunich argues, entertainment producers who market violent videos, movies, and songs to teens should be held responsible for crossing the line into incitement, a category not protected by the First Amendment. So far, victims of violence have had little success convincing courts to override producers' First Amendment protections and hold them liable for copycat crimes.
For example, a Louisiana court ruled last year against Patsy Byers, who sued Oliver Stone and Warner Brothers, the producer of "Natural Born Killers." Ms. Byers was paralyzed in 1995 after two Oklahoma teenagers began a shooting spree after repeatedly watching the film while ingesting LSD tablets.
Even if moviemakers are not legally liable, Professor Helfgott says they should still think more about how violence is portrayed in their films.
"You can make a movie [full of] criminal thinking errors or a movie that makes violence look wrong," she says.