A relaxing evening at a Norwich disco, then the 10.25 p.m. bus back home to Aylsham, Norfolk – this was how Susan Long, 18, spent the last few hours of her life on Thursday, March 10th, 1970. Unbeknown to her a killer was waiting as she got off the bus. He dragged her down a lonely country lane, raped her, strangled her with the straps of her handbag, then tossed her body into a puddle.

Intriguingly, he left his blood on her clothes, and it belonged to a rare group fitting only four per cent of the population. Nearly a thousand local men were examined, but of the 16 of them who were in the same rare blood group, all had alibis.

The following weekend, another 18-year-old girl, Jackie Ansell-Lamb, was raped and murdered in Cheshire after thumbing a lift. Her killer has also never been found. But the case of Susan Long was re-opened in February, 2004, when DNA was extracted from the blood on her clothes. UK Murder Stories from True Crime Library.

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