HE would prey on young girls who were walking alone. Armed with a knife, he would grab and sexually assault them or try to rape them - and in one case his victim was just a child.

Now predator Derek Young is facing a lengthy jail sentence after admitting to his crimes before a court.

Young, 52, pleaded guilty to rape, attempted rape and indecent assault when he appeared before Southampton Crown Court yesterday. The attacks began in 1990 and Young was traced through advanced DNA and forensic work when detectives reopened the case last year.

His first victim was a 19-year-old girl who he targeted in October 1990 as she walked home from a nightclub in Southsea. He stabbed her in the leg and attempted to rape her before she managed to break free.

The victim died 18 months later from an illness which her family have always claimed was made worse by her ordeal at the hands of Young.

Three years later in November 1993 Young - known as "Digger" to his friends - struck again and indecently assaulted a woman.

A year after that, on the night of the first ever National Lottery draw, he targeted a 14-year-old girl who was walking across Southampton Sports Centre's cricket pitch when he pounced. He made her lie on the ground and with a knife to her throat he threatened to kill her and then raped her before running off.

The series of unsolved sex attacks were reopened last year by detectives in Hampshire's major crime department, under the umbrella name of Operation Alveston.

DNA samples were re-examined and, after Home Office funding was secured, they were sent for specialist analysis. The appeal, featured in the Daily Echo last December, was also given high profile coverage by BBC's Crimewatch programme.

Last month, after police had received dozens of calls, they eventually traced Young to his home address in Middle Streets, Southsea, and he was arrested.

He confessed to all three attacks during interviews.

Detective Chief Inspector Rachel Farrell said: "We are really pleased for the victims and their families that Derek Young has pleaded guilty. From a police perspective we are delighted that 18 years after his first offence we have now brought the man responsible before a court."

Det Chief Insp Farrell added: "I have spoken with the victims and families and they are all very relieved that he has been brought to justice. I thank them for their courage and support throughout this investigation."

Judge Derwin Hope adjourned the case for pre-sentence reports to be carried out. Young will be sentenced next month.