John George Haigh (24 July 1909 – 10 August 1949), commonly known as the "Acid Bath Murderer", was an English serial killer during the 1940s. He was convicted of the murders of six people, although he claimed to have killed nine. He did not use acid actually to kill his victims, but rather as (he believed) a foolproof method of body disposal – dissolving their bodies in concentrated sulphuric acid before forging papers in order to sell their possessions and collect substantial sums of money. During the investigation, it became apparent that Haigh was using the acid to destroy victims' bodies because he misunderstood the term corpus delicti, thinking that if victims' bodies could not be found, then a murder conviction would not be possible. The substantial forensic evidence, notwithstanding the absence of his victims' bodies, was sufficient for him to be convicted for the murders and subsequently executed.