A principle of CRIMINAL LAW used to determine the validity of the INSANITY DEFENSE asserted by an accused, that he or she was insane at the time of committing a crime and therefore should not be held legally responsible for the action.
The Durham rule was created in 1954 by Judge David L. Bazelon, of the U.S. Court of Appeals for the District of Columbia, in Durham v. United States, 214 F.2d 862. The rule, as stated in the court's decision, held that "an accused is not criminally responsible if his unlawful act was the product of mental disease." It required a jury's determination that the accused was suffering from a mental disease and that there was a causal relationship between the disease and the act. Because of difficulties in its implementation, the Durham rule was rejected by the same court in the 1972 case United States v. Brawner, 471 F.2d 969 (en banc).
The Durham rule replaced a nineteenth-century test of criminal responsibility called the M'NAGHTEN RULE. The M'Naghten rule, or "right-wrong" test, required the acquittal of defendants who could not distinguish right from wrong. This rule was supplemented by the "irresistible impulse" test, added in the District of Columbia in 1929, which allowed a jury to inquire as to whether the accused suffered from a "diseased mental condition" that did not allow him or her to resist an "insane impulse."
By the mid-twentieth century, these early legal tests of insanity came under increasing criticism. Critics of the M'Naghten rule, for example, charged that it was outdated and did not take into consideration the broad range of mental disorders that had been identified by modern science. Commentators also claimed that these earlier rules did not allow expert witnesses to communicate fully the findings of modern psychology and psychiatry to a jury.
The Durham rule sought to overcome these problems. It attempted to create a simple and open-ended insanity test that would, Judge Bazelon later wrote, "open up the courtroom to all the information and analysis available to the scientific community about the wellsprings of human behavior." Bazelon hoped that the new rule would allow experts to bring to the jury and the public new insights into "the physiological and cultural, as well as individual psychological, factors contributing to criminal behavior." Bazelon intended it to be not a precise test but rather a loose concept comparable to the legal definition of NEGLIGENCE. Thus, he compared the term fault in the negligence context to the term responsibility in the Durham context. The meaning of such terms, he argued, would have to be determined by a jury in light of the facts relevant to each case.
Implementation of the Durham rule ran into serious difficulties. The rule did not elicit the detailed courtroom discussion of mental illness and criminal behavior that Judge Bazelon and others had hoped for. Instead, just as expert witnesses had before been asked the yes-or-no question, "Was the accused capable of distinguishing right from wrong?" experts were now asked the simple yes-or-no question, "Was the accused's act a product of mental disease or defect?" The Durham rule, therefore, perpetuated the dominant role of EXPERT TESTIMONY in determining criminal responsibility, a task that many critics felt was best left to a jury.
As a result of such difficulties, the District of Columbia Circuit unanimously rejected the Durham rule in the 1972 Brawner case. The court replaced it with a standard developed by the American Law Institute: "A person is not responsible for criminal conduct if at the time of such conduct as a result of mental disease or defect he lacks substantial capacity to appreciate the wrongfulness of his conduct or to conform his conduct to the requirements of the law" (MODEL PENAL CODE § 4.01).
This new test has been described as a more subtle and less restrictive version of the pre-Durham right-wrong and IRRESISTIBLE IMPULSE tests. In coming to its conclusion, however, the court in Brawner emphasized that no particular formulation of words provides an easy solution to the difficult problems involved in assessing the sanity of a person accused of committing a criminal act. Instead, the court asserted that criminal responsibility in such trials is best assessed by a properly informed jury that is not overly dominated by expert testimony. To help juries make such assessments, the court required experts to explain the underlying reasons for their opinions rather than giving yes-or-no answers to simplistic questions.