Durham rule

The Durham Rule or "product test" was adopted by the United States Court of Appeals for the District of Columbia Circuit in 1954, in the case of Durham v. U.S. (214 F.2d 862), and states that "... an accused is not criminally responsible if his unlawful act was the product of mental disease or defect". Durham was later overturned in the case U.S. v. Brawner, 471 F.2d 969 (1972). After the 1970s, U.S. jurisdictions have tended to not recognize this argument as it places emphasis on "mental disease or defect" and thus on testimony by psychiatrists and is argued to be somewhat ambiguous.