Haigh was a gambler and by 1947 he was running short of money. To solve his financial troubles, he found another couple to kill and rob: Dr. Archibald Henderson and his wife Rose. After feigning interest in a house that they were selling, he was invited to the Hendersons' flat by Rose to play the piano for their housewarming party. While at the flat Haigh stole Archibald Henderson's revolver, planning to use it in his next crime. Renting a small workshop at 2 Leopold Road, Crawley, Sussex, he moved acid and drums there from Gloucester Road. (Haigh was also known to have stayed at Crawley's George Hotel on several occasions.) On 12 February 1948, he drove Henderson to his workshop on the pretext of showing him an invention. When they arrived, Haigh shot Henderson in the head with the stolen revolver. He then lured Mrs. Henderson to the workshop, claiming that her husband had fallen ill, and shot her also.