“We’re looking for Mr. Steele,” the two men who called at a shop in George Street, Aberdeen, said to the owner. “He’s in one of the flats above your shop.”

“Mr. Steele doesn’t live here any more,” they were told.

A few hours later, in the afternoon of Monday, December 28th, 1964, the tenant of the flat above the shop was found murdered. He was Harold Bruce, a retired painter and decorator now in poor health and living alone. His body was found in the flat the next day by family members.

Was amiable, harmless Harold killed in mistake for “Mr. Steele”? In an attempt to answer that question, police interviewed 6,500 people to no avail.