Known more commonly as “The Acid Bath Murderer”, Haigh managed to carry out several premeditated murders before finally getting caught. In total he killed six people; William McSwan, Donald and Amy McSwan, Dr Archibald Henderson and his wife Rosalie, and Mrs Olive Durand-Deacon. Three of his victims were beaten to death, whereas the other three were shot. When they were dead he would drop the body into a large drum and bathe them in concentrated sulphuric acid until, melting down the body more or less completely.

For quite some time he was not convicted of the first few murders, which were carried out in his plastic fingernail-making factory. However it was the last killing that ended him. Among the sludge a small pebble-like object was found. Pathologist Keith Simpson examined the item carefully and, after analysis, it was confirmed that it was in fact a gallstone. Also found not melted in the sludge were the victim’s dentures, fragments of her foot, pieces of pelvic bone, two discs from her lower spine, as well as a few personal items. Haigh was arrested and sentence to death by hanging. He died on 10/8/49.