The man who killed pregnant mother of two Linda Farrow on Sunday, January 19th, 1975, did it horrifically. He stabbed her repeatedly, then knelt on her back to severe her head with a deliberate sawing action using a razor-sharp freezer knife.

Whatever the motive, it wasn’t sexual. And the man may have known her, for there was no sign of forced entry at her home in Whitehall Road, Woodford Green. Or perhaps he shadowed her home and slipped through the door as she opened it.

Lynda was estranged from her husband and had a boy friend. Both were quickly eliminated from the investigation. The one worthwhile clue: a man seen running down Whitehall Road towards Chingford. He was in his late 30s, 5 ft 9 in, well-built, with an Afro-style haircut, curly and flecked with grey, wearing a workman’s donkey jacket and wellingtons. Does anyone else out there remember him?