The year was 1942. It was Friday, February 20th and London’s Waterloo Bridge was still unfinished. Suddenly, from deep within the blackout and the river mist shrouding the bridge, came the sounds of a row between two people. A shopkeeper investigated and, finding a Canadian soldier the worse for drink on the bridge, escorted him to the south bank.

Half an hour later Canadian Private Joseph McKinstry was seen at Waterloo Station carrying a woman’s handbag. Questioned by a constable, he said he had had a row with a woman who had hit him over the head with the handbag and then run off.

Those were the days of wartime identity cards. The policeman opened the bag and found the card of Peggy Richards, a prostitute living in Deptford. Next morning her body was found on the edge of the river below. It seemed she had been forced over the side of the bridge after an attempt had been made to strangle her.

McKinstry told the court at his trial for her murder that he had twice paid for her services rendered that night, but he hadn’t killed her. There was no proof that he had – it might well have been a later client who came along after he left the bridge. He was acquitted.