Joan Harrison was a poor vulnerable single girl who was murdered by being kicked to death in a disused garage near the centre of Preston on the 20 November 1975.
She had been sexually assaulted to such an extent that semen was found both in her rectum and her vagina .Her killer also bit her deeply on her left breast and stole her jewellery. He ritually placed some of her clothing and shoes in positions which were to be repeated in later murders in Yorkshire. Semen revealed that the killer was of the rare B blood group and was a secretor, that is, one whose semen saliva etc also reveal the blood group. This was a rare individual. One in sixteen people or 6% of all suspects. It was also the key to the police efforts to identify and eliminate suspects. On average 94% of suspects would be outside the frame. The police were confident of identifying him because of the circumstances and the way Joan's purse and handbag were discarded at intervals as her killer walked away from the scene. Unlike many of the later Ripper victims in West Yorkshire, Joan was not a soliciting prostitute looking for motoring punters from the sidewalk.For all these reasons the police were looking for a local man who was not a motorist.
The killer left a deep bite on Joan's left breast showing the track of his teeth revealing a distinct gap of almost one inch between the top front teeth. This bite mark was his signature and if ever apprehended this rare combination of clues was powerful and conclusive evidence to positively identify the culprit. Her purse was found under a hedge a short distance away indicating her killer was on foot and dumped it as he went
