What do you do if you see someone being murdered? On Wednesday, September 29th, 1983, two cyclists in Pitfodels Station Road, Aberdeen, saw a taxi driver in a life-and-death struggle with his passenger. The attacker had the cabby pinned to the ground and was strangling him.

The cyclists sped off to call the police from a phone box. By the time the police arrived the taxi driver, George Murdoch, 58, was dead, and his wallet and some cash was gone.

The killer was shortish, in his twenties, with short dark hair. The description suggests he was probably the same man who went into a fish and chip shop on the Great Western Road in Mannofield about 15 minutes after the murder. Witnesses remembered blood dripping from his hand injury on to the counter, scratches on his cheek and nose and the beginnings of a bruise on the lower lid of one of his eyes.

It was part of the pattern of frustration felt by police that this sighting wasn’t reported until three weeks after it happened. Detectives were astonished that no one in the chippy connected the dishevelled customer to the killing about a mile away. And of the six people known to have been in the shop at the time, only one was traced.