The cultural defense excuses criminal behavior altogether or mitigates criminal liability due to a lack of requisite mens rea based on the defendant's claim that the act is accepted behavior in his/her culture and community. "The term 'cultural defense,' as it is used to describe freestanding defenses raised by criminal defendants who are not part of the dominant culture is a relative newcomer to American legal scholarship." (Maguigan, Cultural Evidence and Male Violence, 1995.) As the United States has become a more diverse and multicultural society, the cultural defense has been promoted as a necessary means of achieving fairness and justice in the legal system.

The general arguments for and against the cultural defense and for its limited use are summarized in this module. Most salient to the subject of this curriculum is the deep concern that because domestic violence and marital rape are so widely accepted in cultures across the world – just as they were until very recently in our own – immigrant defendants can easily use cultural background as a defense to justify or excuse intimate partner battering and sexual assault. See Why Victims Don't Report: Cultural Considerations. For example, sexual assault and kidnapping have been defended as part of a marriage ritual in "marriage-by-capture" cases; similarly, bludgeoning a wife to death after learning of her infidelity has been excused as a normal reaction in a more violent culture.