The well-spoken, public-school-educated son of a solicitor, 27-year-old Alan James Grierson could always spin a good yam. When he met Mary Gann, an impressionable young shop assistant, he told her he’d had a raw deal in life, and she believed him. What he didn’t tell her was that he was a glib, small-time con-man with several convictions.

It was the summer of 1935, and Mary and her elderly mother were looking after a wealthy friend’s flat near London’s Regent’s Park during the owner’s absence on holiday. Grierson persuaded Mary to let him stay there. A few days later he announced that he had got a job as a car salesman, and offered to drive Mary and her mother to the seaside on Saturday, JUNE 22nd. He arranged to pick Mary up at Marble Arch at 1 p.m., saying he would then drive her to Regent’s Park to collect her mother and they would set out for the coast.

Mary waited outside Marble Arch station for an hour. There was no sign of him, so she returned to the flat and found she’d been locked out. She thought her mother must have got tired of waiting and had gone out shopping, so she waited outside for her to return. But Mrs. Gann didn’t come back, and after a while Mary went to a local builder and got him to break into the flat.

They found Mrs. Gann lying unconscious in her bedroom. She had numerous head wounds, and her blood had splashed up the wall and soaked the carpet. She was rushed to hospital, and when the police inspected the flat with Mary they found three empty jewel cases. Some silver plate had been thrown carelessly into a suitcase, and an antique silver cruet was missing.

The police were unable to obtain a photograph of Grierson, but an artist who knew him produced an accurate sketch of him which was published in the Police Gazette. This was the first time the police in Britain had circulated an artist’s impression of a wanted man.

Mrs. Gann died within hours without regaining consciousness, and the murder weapon – a bloodied flat-iron – was found in the kitchen. A photograph of Grierson was obtained a few days later, and when it was published in the Sunday papers this led to his arrest in Weybridge, Surrey, where he had taken a job as a handyman.

The missing silver cruet was traced to a Jermyn Street jeweller who identified Grierson as the man who had sold it to him on June 22nd, and that clinched the case for the prosecution.

Convicted of Mrs. Louise Gann’s murder, Grierson was hanged at Pentonville Prison in October 1935.