Police chief 'wanted to shut down' probe that snared Wimbledon Common killer at centre of Netflix doc

A police chief threatened to shut down the investigation that finally snared the killer at the centre of a new Netflix drama, a former detective has claimed. Robert Napper stabbed Rachel Nickell to death in July 1992 as she walked on Wimbledon Common, South West London, with her two-year-old son, Alex. At the time, another police squad was investigating a series of rapes carried out by Napper but they failed to link him to the crimes after a string of missed chances. He went on to kill Samantha Bissett, 27, and her four-year-old daughter, Jazmine, at their home in Plumstead, South East London, in November 1993. They were among up to 86 women he attacked, stalked or flashed at along London's Green Chain, a linked system of open spaces running from the Thames to Crystal Palace. Napper, then 28, was finally stopped by officers probing the double murder in May 1994. Speaking after the release of the hit series The Witness, ex-Detective Sergeant Alan Jackaman said the breakthrough came a short time after the probe was almost closed. The superintendent in charge wanted to pull the plug after they had failed to find a suspect, he claimed. Mr Jackaman said: "He took me aside and said: 'We are going to have to start closing this down because we aren't getting anywhere'. At the same time there wasn't any press interest and that does drive the job. "I said: 'There's no way we can ever close this down because this bloke is going to do it again and we must get him, we have to.' He said: 'Well I'll leave you to get on with it then but you'll need to get a result fast.'" In November 1989, Napper's mother told police he had raped a woman close to where he would to on to murder Samantha and Jazmine. He had broken into the home of a 30-year-old mum three months earlier and attacked her at knifepoint in bed as her children ate breakfast downstairs. She reported the rape, close to Winn's Common on the Green Chain route, to police but they failed to find a record of it when Napper's mum came forward. Mr Jackaman, author of Napper: Through a Glass Darkly, said: "She said it happened on Plumstead Common which many people call Winn's Common because they are joined so the officer didn't find a record of it." Napper, a paranoid schizophrenic with Asperger's syndrome, continued to attack women at knifepoint, including a young mum pushing her two-year-old daughter, in March 1992. Police linked four terrifying crimes, dubbed the Green Chain rapes, by matching DNA taken from the victims. Then in August 1992 one of Napper's workmates contacted officers saying he looked like an e-fit released of the rape suspect. Around the same time a neighbour separately told detectives she thought the image could be Napper. He was asked to attend two blood tests but he failed to show and fled his flat. Instead of urgently hunting him down, the Operation Eccleston officers dropped 6ft 2in Napper as a suspect because witnesses said the rapist was shorter. The psychopath slipped through the net yet again when he was arrested after asking a printer to copy police notepaper. A search of his flat uncovered a .22 pistol, 244 rounds of ammunition, knives and a crossbow. He was jailed for eight weeks after a psychiatric report concluded Napper was "without doubt an immediate threat to himself and the public". A London A-to-Z map found at his home had spots marked along the Green Chain where he had attacked women and a circle in Richmond Park near the scene of Rachel's killing. Officers did not spot the significance. In February 1993 two boys found a tin containing a World War II gun on Winn's Common. Fingerprints were identified as Napper's but again he was not pursued. Stalker Napper was then spotted climbing a wall to look into a woman's home in July 1993, four months before he murdered Samantha and Jazmine. He was found hiding in an alley on the Green Chain route, and an officer who spoke to him noted: "Subject strange, should be considered as a possible rapist." Despite this, Napper was not referred to the Green Chain detectives. In November 1993 he carried out the Bissett killings. Napper mutilated Samantha's body and sexually assaulted Jazmine before suffocating her. So shocking was aftermath that the police photographer who took the scene-of-crime pictures was unable to work again. Napper was finally arrested in May 1994 after lead detective Micky Banks forced forensic scientists to re-test fingerprints. This led to them discovering they had missed Napper's marks on a window. Mr Jackaman said: "That was the first crime scene that any of us had ever been to where every fingerprint had been eliminated. They had even had a children's party the week before and every kid had been eliminated. "When they did the first examination Napper's fingerprints were confused with Samantha's because they were very similar. A second expert should have checked the work but they didn't. The forensic scientist was adamant he wasn't going to re-test them but Micky insisted." A bloody footprint found in Samantha's flat, also near Winn's Common, matched unusual Adidas trainers whose box was discovered in Napper's bedsit. He later appeared at the Old Bailey where he admitted two offences of manslaughter through diminished responsibility and three rapes. He was sent to Broadmoor indefinitely. But Samantha's mum Margaret Morrison, 53, did not live to see justice after dying of a stroke the previous weekend. Mr Jackaman said: "It was the stress of losing her only child and granddaughter. Napper effectively killed all three of them." Officers soon spotted Napper's likeness to artist's impressions of the Green Chain rapist and the Nickell suspect. And they found the psychopath had marked the Isabella Plantation in Richmond Park on his A-to-Z, close to where Rachel was murdered. Mr Banks was then snubbed by the team investigating Rachel's murder when he told them of his suspicions that Napper was the killer. By that time they were convinced local man Colin Stagg had committed the crime. In 1994 the then Met commissioner Sir Paul Condon said they were not looking for anyone else in connection with Rachel's murder, although Mr Banks and Mr Jackaman disagreed. The case against Mr Stagg collapsed and a police review of evidence finally named Napper as a possible suspect in 2001. Advances in technology could have proven he was the killer that year but the Forensic Science Service missed his DNA when testing samples taken from Rachel's body. New tests in 2002 by an independent lab uncovered a male DNA profile. Intensive forensic work finally revealed there was a one in 1.2million chance that it was not Napper. Particles of red paint in Alex's hair were also found to be identical to the paint on Napper's toolbox. And a footprint from the murder scene matched the shoes he was wearing when he was arrested for the Bissett murders. Napper was finally convicted in 2008 of murdering Rachel. Her partner and father to Alex, Andre Hanscombe told a documentary released with the Netflix drama of his devastation at learning Napper could have been stopped. He said: "The attack that Alex witnessed was preventable, Rachel's death was Andre preventable, Samantha and Jazmine's deaths were preventable."