POLICE are hailing "fantastic" new techniques which helped them snare a rapist 18 years after he attacked a woman.

Martin John-Harris (pictured) has been jailed for raping his 23-year-old victim in a Forest Hill churchyard in July 1988.

John-Harris, of Perry Vale, Forest Hill, was caught thanks to advancements in forensic and DNA techniques.

The case was one of about 300 unsolved rape investigations reopened by the Met Police's Operation Sapphire unit in 2003.

The unit set up the Cold Case Investigation Team with the aim of using advanced forensic techniques to catch sex attackers who had not been caught.

Police took semen samples stored from the scene of the 1988 rape and compared them to the new national DNA database.

They found a match between the sample and the profile of former school caretaker John-Harris.

Detective Sergeant Jackie Murphy says the database, which was set up six years ago, is crucial to the success of the new unit.

She said: "The database is fantastic because it gives victims of unsolved rapes a sense of closure.

"Many still walk down the street in fear, looking over their shoulders. Knowing the culprit is in jail makes them feel safer."

Since the team was set up it has helped jail 17 rapists, sometimes decades after they have committed their crimes.

Det Sgt Murphy added: "The best feeling is when we knock on the culprit's door. They are shocked we have caught up with them.

"They always think they have got away with it."

John-Harris, aged 45, admitted raping and indecently assaulting the woman in the grounds of the United Reformed Church, Courthill Road, Forest Hill.

He was jailed for five years and placed on the Sex Offenders' Register for life at Woolwich Crown Court on April 21.