The single most useful thing about David Canter’s profile was its prediction of where the attackers lived. Before Duffy’s conviction, Canter had been an environmental psychologist. After it he rebranded himself an ‘investigative psychologist’, and devoted much of his time to researching and writing about geographical profiling. Just as law-abiding citizens tend to go back to the same street to do their shopping time and again, most criminals like to commit their crimes in the same areas. They feel safer in places they know. David Canter came up with a circle hypothesis: if you draw a circle with a circumference going through the sites of the two crimes furthest apart from each other, the culprit’s home will likely be near the centre of that circle. Research has shown this to be true of the majority of criminals who strike more than five times. Canter has found that a serial killer can usually be found living within a triangle formed by the sites of his first three murders, as Duffy was. He has developed a computer program, called the Dragnet, which generates ‘hotspots’. Rather than attempting to mark a killer’s home with an ‘X’, Dragnet produces areas showing where he is likely to live, colour-coded from the highest probability to the lowest.
My own close encounter with the use of computer algorithms in tracking serial offenders came courtesy of Kim Rossmo, a detective with the Vancouver Police Department. He was the first police officer in Canada to earn a doctorate in criminology and the research he conducted for his dissertation led him to develop a program that could predict where serial offenders lived. When we met, his system was being beta-tested by burglary investigators who were staggered by the results. I was so impressed by what I saw and heard that I used it as the basis for a thriller, Killing the Shadows, published in 2000, when the idea of geographic profiling was still in its infancy. Years later, I was on a book promotion tour in America when I turned on the TV one morning to see Kim Rossmo being interviewed during the hunt for the Washington Sniper. The bleeding edge had become mainstream in a few short years.
By the time I wrote Killing the Shadows, I had already published two novels featuring clinical psychologist and offender profiler Dr Tony Hill. When I first had the idea for his debut, The Mermaids Singing, I knew I needed help. In the UK, we did things differently from the FBI and the Royal Canadian Mounted Police. We didn’t train cops in behavioural science; we brought practising clinicians and academics in to work alongside experienced detectives. I realised I had no idea how this worked in practice, or what a criminal profiler actually did. The man I turned to for help was Dr Mike Berry. And although I pillaged his working methods, let me say for the record that his personality is different from Dr Tony Hill’s in every significant respect!
Like David Canter, Mike Berry is a psychologist who became involved in offender profiling just as the UK police started taking it seriously. He worked for many years at the sharp end, treating patients in secure mental hospitals before he turned to teaching forensic psychology at Manchester Metropolitan University. Nowadays he’s based in Dublin, at the Royal College of Surgeons.
‘I did my clinical training and undertook placements in clinical departments working with adults, people with learning disabilities and children, and in neuropsychology, before undertaking an elective six months in Broadmoor, working with Tony Black and colleagues.’ Broadmoor is a high-security psychiatric hospital in Berkshire which, since its opening in 1863, has housed the most dangerous criminals in Britain, including Charles Bronson, Ronnie Kray and Peter Sutcliffe a.k.a the Yorkshire Ripper. Years later Mike moved to Ashworth Hospital in Mersey-side, where he worked with some patients displaying extreme behaviour.
Having started their careers in the same era, Mike Berry acknowledges that David Canter’s early forensic work was instrumental both in bringing two murderers to justice, and in boosting the art of geographical profiling. But he sees a flipside: ‘It was too good. It went off too quickly. The press got on to it and then the police fell under a lot of pressure. The media would say, “You’ve had seven days and you haven’t found somebody? When are you going to bring in the experts?” It built up an expectation that you knock on a door of the psychologist and in two hours they’ll solve your murder.’
But then came the case that seriously undermined the public’s trust in offender profiling. On 28 July 1992, the Met Police approached profiler Paul Britton. They needed help catching the perpetrator of an horrific crime committed two weeks earlier on Wimbledon Common, in south-west London. Rachel Nickell, a 23-year-old model with blue eyes and blonde hair, had taken her dog for a morning stroll, along with her two-year-old son Alex. She was passing through a lightly wooded area when a man jumped out at her and viciously stabbed her forty-nine times. In his autobiography The Jigsaw Man (1998) Paul Britton describes how Rachel was found ‘in the most degrading position the killer could manage in the circumstances, with her buttocks prominently displayed … her throat so severely cut that it appeared her head had almost been severed’. Alex was muddied but unhurt. When the next person walked through the trees and came across him, he was crying, ‘Mummy, wake up.’
CSIs found a single shoe print close by Rachel’s body, but no semen, saliva or hair belonging to her killer. Eyewitnesses reported seeing an average-looking man about twenty or thirty years old washing his hands in a nearby stream just after the murder. The media stoked tremendous interest in the case, and one local women’s group offered to donate £400,000 to help the police with their investigation – although they couldn’t accept it.
The police asked Britton to draw up an offender profile. He believed that the killer was a stranger because he wouldn’t have wanted to risk Alex recognising him. He thought he would ‘have a history of failed or unsatisfactory relationships, if any … Be likely to suffer from some form of sexual dysfunction, like difficulty with erection or ejaculatory control …’ Because of the frenzied, disorganised nature of the attack and the lack of an attempt to hide the body, ‘he would be of not more than average intelligence and education. If he is employed he will work in an unskilled or labouring occupation. He will be single and have a relatively isolated lifestyle, living at home with a parent or alone in a flat or bedsit. He will have solitary hobbies and interests. These will be of an unusual nature and may include a low level interest in martial arts or photography.’ At the bottom of his report Britton left a warning: ‘In my view it is almost inevitable that this person will kill another young woman at some point in the future as a result of the strong deviancy and aggressive fantasy urges already described.’ It was in many respects a generic profile, which could have fitted a relatively large number of men.
Within a month of the murder the police had received more than 2,500 phone calls from the public, and were drowning in paperwork generated by the case. They used Britton’s profile to narrow down the suspect list. When BBC Crimewatch featured a reconstruction of the murder, which included an edited version of the profile, three different callers put forward the name of Colin Stagg, 23, who lived by himself on an estate less than a mile from Wimbledon Common. He had told a neighbour that he’d walked through the lightly wooded area ten minutes before Rachel was killed.
In September, when the police went round to Stagg’s flat to bring him in for questioning, they were confronted by a sign on his front door – ‘Christians keep away, a pagan dwells here’. Inside they discovered pornographic magazines and books on the occult. They interviewed Stagg for three days. When they asked him which shoes he had been wearing on the day of the murder, he said that he’d chucked that pair away two days before his arrest. He had had relationships with a few women but he ‘just couldn’t get it up’ with any of them. In the days following Rachel’s murder, he told police that he’d lain out on Wimbledon Common completely naked except for a pair of sunglasses, opening his legs and smiling at a woman who passed by. Stagg repeatedly denied murdering Nickell or being the man seen washing his hands in the nearby stream.
Stagg fitted Britton’s profile closely and so became the police’s prime suspect. But
they didn’t have enough evidence against him. They went back to Britton to see if there was anything he could suggest that could help them build their case. The stratagem that evolved was to use an attractive undercover policewoman in a ‘honeytrap’ sting.
Britton trained the police officer, known as ‘Lizzie James’, in several one-on-one sessions. She was to let Stagg know she was open to things that other people weren’t and give him space to talk about whatever he wanted. Eventually she should tell him that as a teenager she had been lured into an occult group where she was abused and forced to watch the sexual murder of a young woman and child. Since leaving the group, all her relationships with men had failed because none of them had been potent or commanding enough to realise her fantasies for her.
Lizzie wrote to Stagg, who responded immediately. She sent him a photograph of herself and their correspondence gathered pace, with Lizzie encouraging Stagg to relate his fantasies to her:
You asked me to explain about how I feel when you write your special letters to me. Well, firstly, they excite me greatly but I can’t help but think you are showing great restraint, you are showing control when you feel like bursting. I want you to burst, I want to feel you all powerful and overwhelming so that I am completely in your power, defenceless and humiliated.
Stagg replied:
You need a damn good fucking by a real man and I’m the one to do it … I am the only man in this world who is going to give it to you. I am going to make sure you are screaming in agony when I abuse you. I am going to destroy your self-esteem, you will never look anybody in the eyes again …
On 29 April they spoke on the phone for only the second time and Stagg told her a story, in which he entered Lizzie from behind and yanked her head back with a belt. The next day he sent a letter in which he admitted that he had been arrested on suspicion of the Nickell murder. ‘I am not a murderer,’ he added, ‘as my belief is that all life from the smallest insect to plant, animal and man is sacred and unique.’
Five months after the correspondence had begun, Stagg and Lizzie met for the first time, in Hyde Park. She gave him the full account of her occult experience, and Stagg gave her a brown envelope. In it was a vivid fantasy involving Stagg, another man, Lizzie, a stream, a woodland, pain and a knife dripping with blood. At the end Stagg explained that he had written the story because he thought Lizzie would be ‘into it’. The police were excited by this development and Britton told them, ‘You’re looking at someone with a highly deviant sexuality that’s present in a very small number of men in the general population. The chances of there being two such men on Wimbledon Common when Rachel was murdered are incredibly small.’
In August 1993 the police arrested Colin Stagg. Over a year later, when the case finally came to court, Mr Justice Ognall reviewed the 700 pages relating to the case and took a dim view of the trap that the police and Britton had laid for Stagg: ‘This behaviour betrays not merely an excessive zeal but a substantial attempt to incriminate a suspect by positive and deceptive conduct of the grossest kind. The prosecution sought to persuade me that the object of the exercise was to afford the accused an opportunity either to eliminate himself from the inquiry or implicate himself in the murder. I am bound to say I regard that description as highly disingenuous.’ Ognall ruled the letters and taped conversations inadmissible, and Stagg walked free.
In 1998, Lizzie James took early retirement at the age of thirty-three, because of the post-traumatic stress she had experienced since the investigation. In 2002, Paul Britton faced a public disciplinary hearing before the British Psychological Society for offering advice to the Rachel Nickell investigation not backed by accepted scientific practice, and for making exaggerated claims about the effectiveness of his methods. But, after two days, the committee dismissed the case, judging that the eight years that had passed were too long for Britton to get a fair hearing. In those two days the committee also heard that the honeytrap had been approved at the highest levels of the Met Police, and that Britton’s work had been checked by the FBI profiling unit in Quantico, Virginia.
In the same year the police established a cold case review team to look into Rachel Nickell’s murder. Scientists re-examined Rachel’s clothes and were able to produce a DNA profile with the help of a new extra sensitive technique (see p.153). The DNA did not belong to Colin Stagg. It belonged to Robert Napper – a paranoid schizophrenic who had raped as many as eighty-six women across London, before being caught and locked up in Broadmoor. In November 1993, sixteen months after Rachel Nickell’s murder, Napper had brutally killed Samantha Bisset and her daughter Jazmine, 4, in their flat in Plumstead. On 18 December 2008 Napper was convicted of killing Rachel, too.
Forensic pathologist Dick Shepherd did the autopsies on both Rachel and the Bissets. He says that, when he was performing the Bisset autopsies, he remembers remarking ‘“This guy has been here before, whoever did this, this is not the first murder and you are looking for a nasty – what about the Nickell killer? This looks like a progression,” and everybody went, “Oh no, we’ve got Stagg for that, we keep an eye on him twenty-four hours a day.”’ When asked if the murders might be linked, Paul Britton called them ‘a completely different scenario’.
The police had searched Napper’s home in May 1994 and discovered his rare pair of Adidas Phantom trainers. It was not until a decade later that they matched these to the shoeprint left beside Rachel Nickell’s body on Wimbledon Common. In December 2008, an editorial in The Times concluded, ‘The reluctance to investigate Napper for the Nickell murder can be explained only by a belief, shared by the police, Paul Britton and the Crown Prosecution Service lawyers, that they already had their man. In their view Colin Stagg was guilty, so they ignored the material on Napper.’ Stagg was a lonely man desperate to lose his virginity to a beautiful woman. The most explicit sexual story he wrote probably bore such a strong resemblance to Rachel’s murder because he felt Lizzie James was into violent sex and used a local murder whose site he knew as inspiration.
Apart from being a major tragedy for the Nickell and Bisset families, the botched investigation was an expensive embarrassment for the Met. On top of the overall cost of the operation, Colin Stagg was awarded £706,000 in compensation (partly because his name had been so badly dragged through the mud that he never got a job again). Today, profilers are called Behavioural Investigative Advisers (BIAs) and must be accredited. Tellingly, the first guideline for a BIA with the Kent Police is that they ‘[k]now the limits of their expertise and discipline and stay within them’.
In contrast to David Canter’s profile of the Railway Killer, the most unhelpful assertion in Britton’s profile was that the Nickell murderer ‘will live within easy walking distance of Wimbledon Common and will be thoroughly familiar with it’. In fact, Robert Napper had only very recently been forced there after police closed in on his usual hunting ground around Plumstead.
Mike Berry makes a point of visiting the crime scene at the same time of day as the offence was committed because he believes it helps him make tentative judgements about the offender’s relationship to the site of his crime. He says, ‘I remember years ago going down to visit the scene of a crime in a town park. The taxi driver gave me a torch and said, “I’m not letting you go there on your own, you’ll never come out.” It was midnight and pitch black in the park and this was influential in my profile, and I said, “Oh right, that’s all I need to know.” The body was found in a pond in the middle of the park. It became obvious that the person who killed the woman had to be very local to be able to take her there. Daylight pictures wouldn’t have told me how pitch dark it was.’
Early gathering of simple information can provide the sturdy building blocks for a safe offender profile. When there is little forensic evidence to go on, local knowledge becomes even more important. ‘I remember one case,’ says Mike. ‘We talked to the local beat officer and he said that in order to get back from the nearby city nightclubs, youngsters would get a taxi to the top of th
e woods. Then they walk down a path through the woods, stop in a clearing and have a drink and a cigarette there, and then walk on to the village where they live. He said to take a taxi all the way around the woods to the village will cost them twice as much. So the victim – a 16-year-old girl – wouldn’t have been at all worried about walking with somebody in the woods, because that’s what they did. The beat officer didn’t know the importance of what he was saying but he had explained the atypical behaviour. Because the victim was in jeans and a shirt and there was no evidence that sex had taken place, it was suggested that she had rejected his advances and he lost his temper, grabbed her by the throat, strangled her and then walked off home.’ This indicated – along with other factors – that the impulsive, unplanned killing was likely to have been committed by a young male living, or staying over, in the village. It is worth noting that when the police bring in the murder squad, they are all strangers to the district, so talking to the local beat officer will tell you much of the information. The police found the suspect within hours in the village. He fitted the profile completely and was later convicted.