By Reason of Insanity is a 1982 Canadian short courtroom drama television film written by David McLaren and directed by Donald Shebib which examines the use of insanity pleas in murder cases. The film was produced by Alan Burke and made for the anthology series For the Record. Synopsis Teenager Mark Devlin (John Wildman) shoplifts a curved linoleum knife from a hardware store and then, seeing a customer pay for a television set in cash, follows the stranger to the parking lot. He attacks and brutally kills the man impulsively during the robbery by slitting his throat in full view of multiple witnesses and the victim's five-year-old son, who watches in stunned silence. Devlin is arrested almost immediately and charged with first-degree murder, a seemingly open and shut case. Devlin's lawyer is young, bright and ambitious Jane Dexter (Patricia Collins). The only way Devlin can beat the rap is through an insanity plea, as specified in Section 16 (2) of the Criminal Code, which defines an insane person having a mental illness such that he cannot appreciate the "nature or quality of an act". Dexter must therefore argue that Devlin was insane when he killed his victim. There are long preparations to defend Devlin. Psychiatrists try to evaluate him. But it is at the trial where it will be determined whether he is legally insane and therefore innocent or guilty. Devlin's mother (Barbara Williams) testifies that her son was beaten by his father "but it never did any good." She never "really" knew him. He hurt people and "never cared that he did." Devlin testifies that he was unmoved by the killing of a man he did not know: "I didn't feel nothing... It was like a movie. The killing was a movie." The defence psychiatrist (Hrant Alianak) defines Devlin as a psychopath: impulsive, egocentric, and completely indifferent to the reactions of others. Furthermore, he is suffering from a "disorder of consciousness" and entered a "psychotic state" just before he killed. The Crown introduces its own psychiatric evidence. The prosecutor (Michael Kirby) maintains that, since Devlin stole a knife with intent to commit murder, the act was premeditated. The jury must decide whether the accused "appreciated" the nature of his act. Cast John Wildman as Mark Devlin, a "smouldering, sullen" young man on trial for first-degree murder. Patricia Collins as Jane Dexter, a "cool, professional," defence attorney. Michael Kirby as