On the unprecedented nature of the police sting: “This was unique. I don't think there'd been any case where a suspect had been promised sexual intercourse with a police officer if they were to confess to a crime.”
On the targeting of the innocent suspect: “The police are placed under huge pressure and end up arresting somebody, normally the local oddball, working on the assumption that it must be him because we can't find anyone else.”
On the astonishing coincidence that revealed the true killer: “I just thought it highly improbable that there were two people in London at around the same time, murdering mothers in the presence of their children with a savage brutality either on or next to a common.”
NEW PODCAST SERIES: Inside the Case
Second episode: "The Wimbledon Common Murder"
This episode brought to you by The University of Law features celebrated criminal defence barrister William Clegg KC, who successfully defended Colin Stagg - the suspect in the 1994 trial for the murder of young mother Rachel Nickell.
Rachel Nickell, a young mother aged 23, was brutally murdered in July 1992 while walking on Wimbledon Common in broad daylight with her two-year-old son and their dog.
Now, in a revealing new interview, Mr. Clegg recounts the police tactics of entrapment that led to the “local oddball” Colin Stagg being charged; and how a later unconnected case finally revealed the true, dangerous killer to be Robert Napper.
The crime, which involved multiple stabbings and left her toddler clinging to her body, sparked immense media pressure on the police to find the killer.
There were no witnesses and no forensic evidence. “Up against a brick wall,” the police resorted to psychological profiling.
The profile depicted the killer as a single man, sexually frustrated, living by himself. The police eventually focused on Colin Stagg, an unemployed local man seen on the common who fitted this broad description, concluding "it must be him because there is nobody else it could be."
Clegg is dismissive of such profiling techniques - noting that in this case it was so broad it "matched about half a million other people who lived in London.”
With no evidence to charge Stagg, the police launched a highly controversial and unprecedented undercover operation. A female officer, using the alias Lizzie James, contacted him via a lonely-hearts advert to try to get him to confess.
Clegg details the unprecedented tactics, recalling that the officer was "promising intimacy with Colin Stagg... but said she could really only do it if he'd killed Rachel Nickell."
Clegg said: “I remember reading the transcripts of the undercover operation, all of which were taped, and I was completely and utterly astonished. I couldn’t believe what I was reading - that the police had behaved in this way.”
The case collapsed at the Old Bailey in 1994 when the judge ruled that the entrapment evidence was inadmissible. Stagg was released after over a year on remand and received a large sum of money for his story and substantial compensation from the police.
Justice was delayed until 2008, when advances in mitochondrial DNA profiling finally pointed to the real killer: Robert Napper, a man by then already detained in Broadmoor.
Clegg was instructed to defend Napper in an unconnected and equally horrific double murder of Samantha Bissett and her young daughter in 1993.
Reading Napper’s papers, Clegg noticed uncanny similarities between the two cases: both were young mothers, murdered in the presence of a young child, and both crimes occurred on or immediately adjacent to common land. Napper also physically looked very much like Colin Stagg.
Napper, who was severely mentally disturbed and held delusional beliefs—including thinking that "Her Majesty the Queen had been to visit him the week before"—eventually pleaded guilty to manslaughter on the grounds of diminished responsibility for the Bissett murders.
The eventual DNA match confirmed Clegg's strong suspicion, and Napper later pleaded guilty to Rachel Nickell’s murder.
Clegg argues that the tendency for police to arrest the "local oddball" in high-profile cases continues, citing his defence of Barry George (Jill Dando’s murder) and the arrest of Christopher Jefferies (Joanna Yeates’ murderer).
Rachel Nickell’s murder remains a potent reminder of how media pressure and a lack of evidence can risk a spectacular miscarriage of justice.