In the mid-20th century Garnethill, north of Glasgow’s Sauchiehall Street, was a busy, cosmopolitan place well known for the friendly interest people paid in each other’s lives. The area was characterised by steep streets and tall sandstone tenements as well as its transient population of lodgers in boarding-houses and cheap hotels.

Here, on OCTOBER 7th, 1952, one of the children playing in the packed streets from dawn till sundown was pretty, four-year-old Betty Alexander, who lived at 43 Buccleuch Street. That afternoon Betty brought some flowers to her grandmother before going out again to play. She was never seen alive again.

When she was discovered missing all Garnethill seemed to join in the hunt for her. But it took three days to find her body, lying in a deserted hospital courtyard behind a 10-foot-high wall. She had been raped and suffocated.

The clues were all seemingly meaningless. Written on the high wall in white paint were the words, “The Wages of Sin is Death,” but it was never established if this had any significance or not. Betty’s shoes and socks were wet, yet her clothes were dry; a newspaper cutting from a sports section was on her body and, weirdest of all, the pin on her kilt had been changed before her death.

The clues led nowhere, certainly not to her killer, who has never been found.