Who was “A”? That was the vital question occupying the mind of Detective Chief Inspector Jock Jamieson, investigating the murder of bookkeeper Gladys Hanrahan on Friday, October 1st, 1948.

“A” was the initial on the corner of a handkerchief which was forced into Gladys’s mouth while she was being strangled on Cumberland Green, in Regent’s Park, London.

“A” was also the initial of a grocer friend of Gladys who was drinking with her on the morning of her death. He said he had lost the handkerchief some time before. He claimed he went to Brighton after leaving Gladys – an alibi at least partly broken by witnesses who said he was in London. Even so, as the coroner pointed out, there was nothing to connect him with her death.

“A” was also the initial of John Allen, who escaped from Broadmoor a year earlier and who was a prime suspect for the murder of three women in the St. John’s Wood area, including the murder of Gladys. He was re-captured soon afterwards.

And “A” is for anonymous. The killer of 35-year-old Gladys, who lived in North Kensington, has never been traced.