The killer of a young mother, whose death was linked to the Yorkshire Ripper, has been revealed more than 35 years later.

Fresh DNA evidence from the crime scene has led detectives to firmly believe that Christopher Smith bludgeoned to death 26-year-old Joan Harrison, of Preston.

Police said a three-page note by Smith – penned the day before he died from a terminal illness – in which he seemingly admitted the murder was also found at his home, which said: “I can’t go on with the guilt.”

Serial offender Smith, 60, of Leeds, died in 2008 but the Crown Prosecution Service said police had gathered sufficient evidence to charge him with murder had he still been alive.

Mrs Harrison’s battered body was found in a disused lock-up garage in Berwick Road, Avenham, in November 1975.

The connection with Bradford lorry driver Peter Sutcliffe came to light in 1978 – when the serial killer was still at large – as West Yorkshire Police received the first of three letters purporting to be from the Ripper.

It began: “I am sorry I cannot give my name for obvious reasons. I am the Ripper” and later added: “Up to number eight now you say seven but remember Preston 75, get about a bit you know.”

Following Sutcliffe’s capture and confession, the messages were later proved to be from hoaxer John Humble, known as Wearside Jack.

In 1981 Sutcliffe was jailed for life for murdering 13 women and attempting to kill seven more, while Humble, of Sunderland, was jailed for eight years in 2006 for perverting the course of justice.