John Knatchbull (c. 1792-1844), naval captain and convict, served in the British navy before being convicted of stealing and transported to New South Wales. He became constable to the Bathurst - Mount York mail service and an overseer on the Parramatta Road before being convicted of forging. Sentenced to death, he was sent to Norfolk Island instead. Here he was involved in a mutiny, but escaped justice after turning informer on his fellow mutineers. He obtained his ticket of leave in 1843, but the following year he was arrested for the murder of a woman. He was defended by Robert Lowe, later Britain's Chancellor of the Exchequer and Home Secretary, who for the first time in a British court raised the plea of moral insanity (insanity of the will, as opposed to the intellect) in the case. Despite this plea and a subsequent appeal, Knatchbull was hanged in February 1844.
