List of serial killers who used the insanity plea in their defense. Although pop culture often depicts the insanity plea as a common occurrence in the legal universe, it’s actually one of the rarest methods of defense. In order to prove an insanity plea, the defense must show that the killer either did not realize what he or she was doing, but also that they didn’t know the difference between right and wrong. Very few insanity pleas have worked in murder defenses and even fewer in the case of serial killers. Most killers who have pleaded insanity have found themselves with a death sentence anyway.
When there is mounting evidence against a serial killer, sometimes the insanity defense is the best way to try to stay off death row.The defense, however, ensures that the criminal must admit that they committed a crime, so a later not-guilty plea is difficult or impossible. Even in cases where a killer has been found not guilty by reason of insanity, serving time in a mental hospital is required. In some cases, like with Albert Fish, the jury may acknowledge the killer is insane, but find them guilty anyway.
Which serial killers have plead insanity? The dangerous killers on this list used insanity pleas to defend themselves in court.
8 Serial Killers Who Plead Insanity,
Albert Fish
Albert Fish bragged about raping children in every state, but he only had 3 known murder victims. Fish claimed that God told him to kill children, so he pled insanity in his trial. The jury believed that Fish was insane, but wanted him executed anyway so they found him guilty. He was sentenced to death and executed in 1936.
Andrea Yates
Andrea Yates drowned her five children in the bathtub. She was convicted in 2002 and sentenced to life in prison. Since she was suffering from postpartum depression, she was able to plead insanity in a 2006 retrial. Yates is currently in a mental hospital.
David Berkowitz
David Berkowitz, aka Son of Sam, claimed that a demon dog told him to kill young girls. Psychiatrists called him delusional, but the courts allowed him to stand trial. He spent a few months at a psychiatric hospital, but was transferred to Attica soon after.
Ed Gein
Ed Gein is best known as the inspiration for the Texas Chainsaw Massacre's Leatherface and Norman Bates. Gein was caught for killing at least two people, but there were the remains of far more people used as everyday objects in his home, including masks, belts, and window shades. He pled not guilty by reason of insanity and was found unfit for trial. He spent the rest of his life in a mental institution.
Jeffrey Dahmer
Jeffrey Dahmer murdered, dismembered, raped, and cannibalized 17 men between 1978-1991. He pled not guilty by reason of insanity but he was still convicted to life in prison.
John Wayne Gacy
John Wayne Gacy killed at least 33 men in the early 70s. During his 1980 trial, he plead insanity with his defense arguing that he was a paranoid schizophrenic. Gacy later wrote a letter to the judge claiming that the insanity plea was made without his approval. Gacy was sentenced to death and was executed in 1994.
Kenneth Bianchi
Kenneth Bianchi was one of the Hillside Stranglers, who killed and raped at least 12 women. Bianchi originally tried to claim that he suffered from multiple personality disorder, but was caught in his lies when a psychiatrist, Martin Orne was brought in. He was sentenced to life imprisonment.
Anthony Sowell
When Anthony Sowell was on trial for killing 11 women, he pled insanity. Ultimately, Sowell, who buried the bodies around his Cleveland home, couldn't prove that he didn't know the difference between right and wrong and was convicted.