THE detective who caught double murderer Christopher Halliwell has told how a stash of sketches may give vital clues to the places where other victims are buried.

In an interview with the Sunday People, Steve Fulcher said a stash of puzzling pencil drawings was seized at Halliwell's home and he believes the sketches of rural scenes could help police to uncover more murders.

Former taxi driver Halliwell was told last month at Bristol Crown Court that he must spend the rest of his life in prison for the murders of Becky Godden in 2003 and Sian O’Callaghan in 2011.

But Mr Fulcher said a forensic psychologist helping with the investigation believed the killer probably drew the sketches as macabre trophies of his crimes.

Mr Fulcher said: “There were a good dozen or so sketches that I saw and they were all of remote locations. One of my lines of inquiry was obviously to try to identify where these places were.

“All the evidence pointed to there being more victims. The theory I was working on was that if I could find those locations I could find other victims.”

Mr Fulcher – whose resigned after he broke Police and Criminal Evidence Act guidelines while nailing Halliwell – called in experts to help identify the locations and supplied sketches to other police forces.

Karen Edwards, whose 20-year-old daughter Becky Godden was sexually assaulted and strangled by Halliwell, said: “I think it is disgraceful but not surprising.

“Wiltshire Police obviously think they have their man now and don’t have to follow up any more leads. But what about closure for other people?”

Halliwell, 52, formerly Ashbury Avenue, Nythe, was already in prison for killing 22-year-old office worker Sian when he was charged with Becky’s murder.

Both Mrs Edwards and Mr Fulcher believe police should have done more to investigate him over the disappearance of other women.

Mr Fulcher has branded the Wiltshire force investigation a “shambles”.

Recalling Halliwell’s sketches, he said: “I got a forensic psychologist to give me a hand. He said things like sketches could be sexual triggers subsequently. So he would look at a scene he has drawn and recall a victim and that would engender a sexual response.”

Mr Fulcher believes Halliwell could solve the mysteries of at least three missing women. Two vanished on the same date as Sian but in different years.

Linda Razzell, 41, went missing from her home in Swindon on March 19, 2002. Her husband Glyn Razzell was jailed for life but has always claimed his innocence.

Chef Claudia Lawrence, 35, disappeared on March 19 in York in 2009.

That was also the date Sian O’Callaghan disappeared in Swindon in 2011.

Halliwell had been dumped by a girlfriend in the 1980s – on March 19.

He has also been linked to the disappearance of prostitute Sally-Ann John, 23, in Swindon in 1995.

Mrs Edwards, 55, said after Halliwell was convicted of her daughter’s murder: “I believe he has been up and down the country murdering young women. Serial killers are triggered by dates."

Wiltshire Chief Constable Mike Veale insists that his force has no evidence to link Halliwell to any other murders and has praised the investigating team.

But Mr Fulcher added: “I am going to be taking this through the political process, through my MP Sir Nicholas Soames, because I have good information that the stance taken by Wiltshire Police is not true.

"I shall be asking for it at the most senior level of government.”

Mr Fulcher is now a security consultant in Africa.