On the evening of Jan. 19, 1931, the Liverpool Chess Club took a telephone message for one of its members. The caller, an R.M. Qualtrough, said he wanted William Wallace to visit him the following evening at 25 Menlove Gardens East to discuss insurance.

Wallace arrived 25 minutes later and took the message. The following evening he made his way into Liverpool by tram, only to discover that no such address existed. He made inquiries with a local policeman and a newsagent, then returned home and found that his wife had been beaten to death in their sitting room.

Had Wallace manufactured an alibi and then killed her himself? The telephone call had been placed from a box only 400 yards from Wallace’s house, but the message taker was certain the caller had not been Wallace. The crime scene was quite bloody, but no traces of blood were found on Wallace’s suit. A milk delivery boy insisted he had spoken to Julia Wallace only minutes before her husband would have had to leave to catch the tram.

Wallace was found guilty and sentenced to death, but an appeals court quashed the verdict on the grounds that it was unsupported by evidence. Wallace went free and died in Wirral in 1933. The crime remains unsolved.

If Wallace killed his wife, how did he manage it? If he didn’t … who did?