As reported by Liverpool Echo, a serial burglar, nicknamed the Anfield Housebreaker, was active in the area at the time Julia Wallace was killed. Although William noted some money was missing from the home, and some of their belongings appeared to have been rifled through, authorities determined the details of the case were not similar to the Housebreaker’s other crimes.

In 1984, author Roger Wilkes suggested William’s former co-worker Richard Gordon Parry may have been responsible for Julia’s death. As reported by Unsolved Casebook, Parry was questioned amid the investigation into Julia’s murder. According to witness reports, Parry took his vehicle to a car wash on the evening Julia was killed. The witness claimed they found bloody gloves inside Parry’s car.

It has been suggested that Parry may have killed Julia when she caught him stealing money, or the two may have been having an affair. However, he was ruled out as a suspect when his fiancée, Lily Loyd, provided him with an alibi. Unsolved Casebook reports Loyd later admitted she lied about being with Parry when Julia was killed, but authorities had already built a case against William.

Unsolved Casebook reports the Wallaces’ neighbors, Jack and Florence Johnston, have also been accused of killing Julia. Author Tom Slemen said Jack confessed to the murder while on his deathbed. According to Slemen, the Johnstons planned to rob the Wallaces, and were unaware Julia was home.