Thirty years on, a middle-aged business executive has been arrested and jailed to await trial after being identified as the killer by a new computerised records system. The case is regarded as one of the more unusual in the city's lurid criminal history.
It all comes down to fingerprints. Two years ago, the police fed details of 50 unsolved murders from the early Sixties into their new state-wide fingerprint computer network to see if any of their ageing prints came up with a match. One did. Prints found at Thora Rose's flat seemed to fit those of Vernon Robinson.
Mr Robinson, a 48-year-old divorcee with three grown-up children, was traced to his riverfront home in Minneapolis, where he was working as a dollars 70,000-a-year executive for a building firm. His arrest came as a shock: although he had previous convictions, he had not been in trouble with the law for 25 years and had become a respected figure in the Methodist Church. 'It is a complete nightmare to him,' said his lawyer. 'He cannot believe what is happening to him.'
Mr Robinson was a naval rating in San Diego at the time of the murder and claims he spent the evening at his base. After reading about the case a short while ago, a former fellow rating came forward to testify that all the sailors were in quarantine at the time because of an outbreak of meningitis.
However, the witness later died in a boating accident. Naval records are too old, or incomplete, to clear up the issue. In addition, many witnesses have died, or forgotten what happened, and much of the forensic evidence has disappeared.