Britain's leading criminal profiler advised detectives to investigate clues linking the murder of Rachel Nickell with the brutal killing of another young mother - but they dismissed any connection, The Independent on Sunday can reveal.
The claim follows Scotland Yard's revelation that detectives believe one man - Robert Napper - may have been responsible for both the murder of Ms Nickell on Wimbledon Common in 1992 and the slaying of Samantha Bisset and her four-year-old daughter Jazmine nearly a year and a half later.
Napper, who is detained indefinitely in Broadmoor, convicted of the Bisset murders, is also suspected of being the Green Chain rapist who carried out at least 70 savage attacks across south-east London in a four-year spree more than 10 years ago.
There are striking similarities between the Green Chain rapes, the Bisset murders and the killing of Rachel Nickell: all featured savage sexual assault and, in the case of Ms Nickell and Ms Bisset, extreme mutilation.
Detectives are waiting to interview Napper, who emerged as the main suspect for the Wimbledon Common murder after police-enhanced traces of DNA were found on Ms Nickell's clothes. The new lead has reignited accusations that murder squad officers bungled the case and pursued the wrong man. Colin Stagg, who was charged with Ms Nickell's murder, could receive £500,000 in compensation.
Now Paul Britton, who was brought in to help solve all three cases, has told the IoS that the Bisset murders could have been prevented if investigators had acted earlier on the Green Chain rapes.
"Samantha Bisset would never have been killed if my early advice had been acted upon and, if it is the same person, then neither would Rachel Nickell," said Mr Britton, the psychological profiler on whom the television series Cracker was based. "I sometimes wish I'd gone back and banged on their [the police's] door."
Mr Britton was brought in at an early stage to advise on the Green Chain rapes, which began before the murders of Ms Nickell or the Bissets. He gave police three pointers which he said would lead them to the rapist: the attacker would already be on their records for minor offences, he would have been noticed by neighbours, and his suspicious behaviour would have been mentioned at local police briefings.
"To this day I do not understand why this did not happen," said Mr Britton, who advised police in both the Jamie Bulger murder case and the hunt for Michael Sams, who is serving four life sentences for the murder of Julie Dart and the kidnap of Stephanie Slater.
"We were looking at an escalating offender. My advice was to look at the case from a local level."
Napper was brought to justice for the murder of Ms Bisset and her daughter after detectives found his fingerprint on a balcony at the back of Ms Bisset's basement flat in Plumstead, south London. He never confessed to the Green Chain rapes.
The original prime suspect in the Wimbledon Common murder, Mr Stagg became the focus of a sting operation by the Metropolitan police where a female undercover officer was used to befriend the loner in the hope he might confess to murdering 23-year-old Ms Nickell, who was stabbed 49 times as she walked on the common with her young son and dog.
Operating under the name "Lizzie James", the officer wrote a series of sexually intimate letters to Mr Stagg. He never confessed but was charged - only for the case to be thrown out by a judge in 1993 on the grounds that the police had used entrapment.
It has always been assumed that Mr Britton, who drew up a psychological profile for police of the Wimbledon Common killer, wrote the Lizzie James letters, but he revealed that this is not true and also said that he questioned the legal basis for using a sting operation to extract a confession from Mr Stagg.
"Not only did I not write them but I did not see them until they had been sent. It was never my notional suggestion that it would be a good idea to write the letters," said Mr Britton. He was exonerated of any wrongdoing in 2002 over the Wimbledon Common case after an eight-year inquiry by the British Psychological Society.
The forensic profiler, who examined 14 hours of taped interviews with Mr Stagg, said that the undercover operation was presented to a top-level police meeting where it was given full approval.
"My first question was, 'Is this legal?' What the police said echoes for ever: 'Please don't concern yourself with legal issues,'" said Mr Britton who still advises British and overseas police.
"This case was at the very top of the then Attorney General's watch list. The highest legal authorities in the land were involved. One of the myths that has been allowed to perpetuate is that they [the police] were a bunch of mavericks. They were fully monitored at higher levels."
The Met said yesterday that there were not prepared to comment on an ongoing investigation.
The Wimbledon Common killing received widespread coverage because of the horrific details of the attack, which was witnessed by Ms Nickell's two-year-old son Alex. He was later found clinging to his mother's blood-soaked body begging her to get up.
The month after the murder, Napper was taken in for questioning about the Green Chain rapes after a tip-off from a suspicious neighbour, but he was released after he persuaded detectives they had the wrong man. He offered to give a blood sample, which would have determined his guilt, but failed to turn up and provide the specimen and was never chased up by officers.
The controversy over the handling of the murder of Ms Nickell, a part-time model, had a lasting affect for many on the case. The female undercover officer, whose identity has never been made public, was offered a rumoured £200,000 in compensation from the Met after claiming the case led to stress and depression. In 1998, she left the force and never returned.
Mr Britton admits that he found it difficult at times to deal with the criticism and now says he would have preferred to put his side of events earlier but was told by the Met to stay silent.
However, he also says that there is very little he would have changed about the investigation, which he describes as "groundbreaking" in its use of psychological profiling. "It's a tough world and it was all most unpleasant, but what I can never get away from was what the poor Nickell family will have to go through for the rest of their lives," he said.
In his opinion, the Government should set up an accredited list of official psychological profilers to bring the image of their role out of the realms of "witchcraft and mysticism" - but he has no desire to be on the list. "It's a dreadful task. You get a phone call and it's a police officer saying someone has been horribly slaughtered. It's like plunging into a psychological sewer. You don't think, 'Whoopee, isn't this great.'"Reuse content