POLICE are appealing for women to come forward if they think they may have been a victim of sex beast John Walker.
Officers have combed through cases involving unsolved rapes on their files and ruled Walker out.
But they know that many sex attacks go unreported, and the discovery of the knock-out drug chloroform and photos of young girls at the time of his arrest set alarm bells ringing.
The 51-year-old father of two, who rents an apartment in Moor End Lodge, part of the luxury redevelopment of the former Kodak site, has admitted carrying out two rapes in the late 1980s and is due to be sentenced next month.
Herts police spokesman Olivia Finucane said: “We looked at him and did a lot of work and found there were no outstanding offences in Herts that he could have committed.
“We have not ruled him out. If anybody thinks they have been a victim of him please come forward because we want to hear from you.”
Thames Valley Police began working to solve the cold case three years ago.
The key to cracking the crimes was DNA, which linked the rape of a 25-year-old woman in Wembley in 1987 with an attack on an 18-year-old woman at Marlow railway station in Bucks 18 months later.
Pete Beirne, principal investigator for the force’s Major Crimes Review Team, said: “We were aware that the Marlow rape was linked forensically with the rape in Wembley.
“There were samples taken during the original investigation and subsequently full DNA profiles were obtained.
“In the late 1980s DNA was in its infancy.
“They were able to get a profile but there were very few people to check that against because the database was not as big as it is now.”
However, fresh work with the database produced a list of 400 people who could be linked to the offender and this was eventually whittled down to a member of Walker’s family, whose DNA had been taken following a recent offence.
Investigators also discovered Walker, who works for an electricity company, had been convicted of rape in 1979, before the creation of the DNA database, and that he was from the Wembley area.
“He then became a very strong suspect,” Mr Beirne said.
“We arrested him, swabbed him. That was analysed and came up with an exact match.
“The fact he has now been convicted of three stranger rapes where victims were attacked while out on the streets coupled with what was found in his van at the time of his arrest does cause us concern to the danger he poses.
“We are pleased with the conviction we obtained and hopefully we have stopped other people being attacked by him.”