John E. DuPont Trial: 1997

On February 25, 1997, the jury found DuPont guilty of third-degree murder and simple assault, under Pennsylvania's guilty but mentally ill statutory scheme. In Pennsylvania, "guilty but mentally ill" means that a defendant who offers a defense of insanity in accordance with the rules of Criminal Procedure may be found "guilty but mentally ill," at trial if the trier of facts finds, beyond a reasonable doubt, that the person guilty of an offense was mentally ill at the time of the commission of the crime and was not legally insane at the time. "Mentally ill" means that as a result of mental disease or defect, a person lacks substantial capacity either to appreciate the wrongfulness of his or her conduct or to conform his or her conduct to the requirements of the law. Whereas, under the more widely known "not guilty by reason of insanity," the person who committed the crime is incapable of understanding the nature of his or her actions, or if he or she does understand them, cannot understand that they are wrong. The statutory maximum sentence for third-degree murder in the state of Pennsylvania is 40 years in prison.

On May 13, 1997, DuPont was sentenced to 13 to 30 years for the murder conviction. He also received a concurrent sentence of three to six months on the assault conviction and was ordered to pay costs incurred by the district attorney's office in connection with his prosecution.

The John DuPont case once again focused attention on the use of the insanity defense and was one of the first high-profile cases to be tried under the new "guilty but mentally ill" statutes that 12 states had enacted following John Hinckley's attempted assassination of Ronald Reagan.