Screams of “Oh, John, don’t! You’ll kill me!” brought a neighbour running into a caf? at Norton Folgate, Shoreditch, London. There was little he could do. The caf? owner’s wife, Emma Grossmith, 45, was lying unconscious on the floor in a pool of blood. She had been battered over the head with a rolling pin and a poker.

The caf?’s odd-job man, Alexander Mackay, 19, who everyone called John, told the neighbour: “It wasn’t me. I had nothing to do with it,” and promptly fled into the street.

Emma died a week later in hospital and for several weeks the police were unable to trace Mackay. They finally found him locked up inside Maidstone Prison – immediately after the attack on Emma Grossmith he had been arrested for theft and jailed.

The caf?’s owner, George Grossmith, who was out at the time of the attack on his wife, said: “There was animosity between my wife and Mackay ever since he began working for us. She had to criticise his work constantly.”

Mackay was sentenced to death at the Old Bailey and hanged at Newgate on Tuesday, September 8th, 1868. This was the first execution in London within prison walls since the law was passed banning public executions. In the death cell Mackay became so frightened he had to be dragged to the gallows.