When he left the crime scene, the killer of Joy Sweatman was seen to be wearing a fawn coat and flat cap, was wiping a hammer which was undoubtedly the murder weapon, and appeared to have red paint on his face – which could have been blood. He was also seen getting into an R reg white Austin Maxi saloon.

And then he vanished. Even when each of the 3,500 owners of white Maxis in mainland Britain was checked, nothing surfaced.

His attack on Joy at her home in St. Andrew’s Road, Coulsdon, Surrey, on Wednesday, June 1st, 1977, was truly ferocious. She was first struck while standing up, next beaten with the hammer, and as she fell to the floor the killer stamped on her body, leaving her dead with a pillow and a plastic bag over her head. He also attacked her five-year-old daughter so badly that the child was unconscious for four days. The crimes were discovered by Joy’s lodger when he returned home at about 1.30 p.m.