The Insanity Dodge.

Insanity was seldom a popular defense to murder -- while defense attorneys used terms like temporary insanity, transitory frenzy, and monomania, to the press and the public it was “the insanity dodge.” The first successful use in America of temporary insanity as murder defense was the trial of Dan Sickles for the 1859 murder of Phillip Barton Key. Sickles appeared perfectly sane at his trial but claimed that his wife’s infidelity had temporarily made him unable to tell right from wrong. 

Here are a few cases using the insanity dodge with varying degrees of success:

	Dan Sickles's Temporary Insanity. 1859 - First successful use of the temporary insanity plea in America.
	The Worst Woman on Earth. Lizzie Halliday unsuccessfully pled insanity for the murder of her husband and two servants in 1893. She was convicted of first-degree murder and sentenced to the electric chair but the governor commuted her sentence and sent her to an insane asylum. There she murdered her nurse.
	Crazy John Daley. John Daley, known as “Crazy John," pled insanity for the axe murder of his wife in 1883 and was easily acquitted. “Daley became a homicidal maniac through a frenzy of religious excitement.” Said the press.
	Shot by a Jealous Husband. When Daniel Monahan shot his wife for adultery in 1886, the public viewed the murder as justified. He was acquitted on the grounds of insanity and the verdict was well received.
	Transitory Frenzy. Charles Henry was obsessed with actress Effie Moore. She led him on for a few weeks, but when he learned she was already married he shot her. He pled not guilty by reason of “transitory frenzy”; to everyone’s surprise, the verdict was not guilty.
	A Contract with the Devil. Joseph E. Kelley murdered Joseph Stikney during an 1897 bank robbery. He pled guilty but during sentencing medical experts described him as “A high-grade imbecile” “about 8 or 9 years old, mentally and morally.” Their diagnoses saved him from the gallows but he was sentenced to thirty years in prison.