The scene was London’s Blackheath Common, where a woman’s body lay under a coat on a footpath. The discovery was made by a lamplighter at around 7.40 a.m. on JANUARY 23rd, 1931. The woman’s clothes had been ripped off, her face and neck mutilated, and she had been strangled.

She was identified as Louisa Steele, 19, a live-in domestic servant employed by Kathleen Andrews, a professor of music in Lewisham. She had set out the previous evening on a couple of errands, and was reported missing when she failed to return home by 1 a.m.

Several witnesses had seen a distressed girl with a man on the common on the night in question. The man was described as about 25, five-foot-eight, and clean-shaven with a scratch on the right side of his face. The girl with him had addressed him as Jack, and an unfinished letter beginning “Dear Jack” was found among Louisa’s belongings.

So far as her employer knew, however, Louisa had no boyfriends, and it was discovered that she had completed only one of her errands. At the inquest a detective said the murder was the work of a maniac.

The case was never solved, but in his memoirs Scotland Yard’s Superintendent Arthur Fowler Neil wrote that “an educated man of a well-to-do family was strongly suspected, but proof was lacking.” The man had been discharged from a private mental institution into the care of his family. Immediately after Louisa’s murder, the superintendent wrote, “he was back again in his private mental home, and the authorities will see that he does not come out again.”