In the 1920s Blossom Alley, a narrow passageway between North Street and Cross Street not far from Portsmouth Docks, was, despite its name, regarded as the worst slum in Portsmouth. It was the haunt of prostitutes, and it was here that on JANUARY 27th, 1923, someone battered prostitute Mary Pelham to death, adding for good measure an attempt to strangle her with a scarf.

Police at once suspected a sailor, for Mary frequently took sailors home, and several women claimed that they had seen her with a sailor on the night of her death.

A few days after her body was found an identity parade of every man at the Royal Naval Barracks was called out — all 3,500 of them. A sailor was identified, but had a satisfactory explanation for his whereabouts.

So could the killer have been a civilian? The scarf around Mary’s neck was of a type often worn by working men, and was tied with a granny knot, which a sailor would not have used.

The question was never answered, for the murderer was never found. And a few years later Blossom Court vanished forever in a redevelopment scheme.