Alan Blackwell admitted the attempted rape

Alan Blackwell, from Jarrow, in South Tyneside, was traced by Northumbria Police officers through Operation Phoenix.

This uses modern forensic techniques to re-investigate unsolved sex crimes.

At an earlier hearing at Newcastle Crown Court, Blackwell admitted trying to rape a 19-year-old woman in South Shields in June 1994.

The case was investigated at the time but remained unsolved.

I would like to reassure victims and warn offenders that time is of no consequence Detective Inspector Garry Dixon

However, some of the original evidence was subject to new forensic analysis, leading to a full DNA profile being obtained, which was matched to Blackwell.

Detective Inspector Garry Dixon, who heads Operation Phoenix, said on Friday: "Our community is a safer place as a result of this conviction for an atrocious attack on a defenceless victim. Our thoughts go out to her.

"Operation Phoenix is the renowned leader of cold case reviews in the UK and it has received many plaudits, both nationally and internationally.

"I would like to reassure victims and warn offenders that time is of no consequence.

"By using the technology of today to solve the crimes of the past, we're helping to prevent similar crimes in the future."