Crime story

x Sponsored content on Research Live and in Impact magazine is editorially independent.
Find out more about advertising and sponsorship.

David Canter always wanted to be a psychologist – but when the police knocked on his door in the mid-1980s, asking for his help to catch a killer, it marked a turning point in his career.

Up to that point, Canter’s focus had been on the psychology of architecture. “I actually wanted to study the psychology of art, but I couldn’t get any funding to do a PhD in it,” he explains. “But I could get funding to work on the psychology of architecture.”

He spent more than a decade investigating the relationship between people and the environments in which they live, and how they interact with buildings and spaces within those environments.

A year in Japan, working with a building research institute, was followed by a decade back in the UK, working with a British equivalent.

“I was doing research on fires in buildings, in which there had been fatalities,” says Canter, “and one of the things I became aware of was that the design of buildings in Britain was very much shaped in relation to fire regulations, and how people could best escape a building in the event of an emergency. But the basis for this was very weak – just a few actual incidents, no real systematic psychological study.”

Canter explained the work he was doing at this time in a 1998 interview with BBC Radio 4. He said: “The assumption is that the minute anybody has a whiff of smoke, or sees a flame, they run out screaming in panic. Which of course is not what happens at all. People try to cope with emergencies in the most remarkably sensible way… And, really, what you need to do is to shape buildings – and the whole management process – to take account of the fact that people will try to make sense of what’s going on, and do the most effective thing they can in the light of the knowledge that they have.”

In trying to build up a more accurate picture of people’s behaviour during emergencies, Canter came into regular contact with police case files. “In Britain – if there is a fatality in a fire – the police carry out an investigation, as if it was a murder inquiry,” he explains. “Once the inquiry is over, there are all these witness statements of people explaining what they did. So that’s what I started to work on.”

This exposure to police records would come in handy in 1986, when Canter was approached by murder detectives, who wanted to see whether psychological profiling was as useful a crime-fighting tool as American law enforcement was making it out to be.

To catch a killer

Anne Lock was a 29-year-old, recently married secretary, who had just returned from honeymoon when she was abducted, raped and murdered in May 1986. Her body wasn’t discovered until July; however, police had already connected her disappearance with the rapes and murders of 19-year-old Alison Day, and 15-year-old Maartje Tamboezer. Detectives also suspected that the murders were linked to a series of rapes – up to 30 – going back several years.

Police had a long list of suspects – 1,999 – but needed help to narrow the search. So they contacted Canter, who, at the time, was a professor of applied psychology at the University of Surrey. He was approached, he says, “because I’d been working with police statements in the fire research; I had an idea of how to work with this material”.

On joining Operation Trinity, he began studying the case files – and a map of all the linked attacks – in an attempt to identify the killer’s base. For this analysis, Canter drew on the theories he had laid down in his 1977 book, The Psychology of Place, which he describes as “an exploration of how people make sense of their world”.

“I thought of this criminal as making use of his surroundings like anyone else in his situation might,” wrote Canter in a 2006 paper. “This enabled me to make sense of the pattern of rapes and murders, in order to determine where the offender may have lived at the time of his offences. This turned out to be very helpful to the police.”

That’s probably an understatement. The psychological profile drawn up by Canter, based on this analysis, helped focus attention on one man, John Duffy, who matched 13 of Canter’s 17 profile pointers. Duffy was convicted in 1988 of two murders and four rapes, and later named his accomplice, David Mulcahy, who was convicted of three murders and seven rapes.

Canter’s success in the Railway Rapist case, as it became known, laid the foundations for investigative psychology in the UK. However, he’s keen to stress that: “I don’t believe in the idea of ‘the profiler’ – of a person going in and giving advice to the police in a particular investigation.” Rather, he sees his work as providing a framework for developing and guiding police activity.

“When I’m asked: ‘At which stage in an investigation should you call in a psychologist?’ I always say: ‘Before the crime is committed.’ British police have graduates of mine working with them as ‘behavioural investigative advisers’
– which is much more sensible than ‘profilers’ – as they are actually giving guidance for what the investigative directions can be, rather than just giving a pen portrait of the individual.”

Here, Canter draws parallels with market research work he conducted earlier in his career, “as a psychology postgraduate trying to earn a crust”. Indeed, prior to his work on Operation Trinity, Canter had completed a research project looking at people’s conceptualisation of biscuits.

“It’s all very well drawing up a profile of a likely consumer,” he says, “but what you want to know is: what do you do about it? How do you reach them? What issues are going to be relevant?”

Canter believes his market research experience gave him a different perspective on criminals. “All the psychologists who had been involved in studying criminal behaviour up to that point had been clinical psychologists; people who regarded criminals as mentally disturbed in some way,” he says.

“But because I’d worked in market research, what I brought to it was an awareness that criminals were, in some ways, ordinary people who were doing things we could understand from an ordinary perspective. What they were trying to do was, of course, unacceptable and against the law – and often why they were doing it would be difficult to understand. But what they were doing – what they were trying to achieve – I thought we could actually get a grip on very readily.

“The market research idea – that we can understand a lot about people based on what they do – is central to my work,” adds Canter, who calls it “the consistency principle”. “The best prediction of future behaviour is past behaviour. The whole idea that we are slaves to our habits, and our ways of dealing with the world – that is my starting point for thinking about criminal behaviour.”

The consistency principle

There are two distinct aspects to Canter’s work. “One is behavioural, the other is geographical. These overlap and feed on each other, but the behavioural issue is a matter of identifying the salient features of any criminal activity,” he explains.

“What we’ve shown from statistical models, is that if you take any set of similar crimes – burglary, arson, serial killing – what you find is that there are a set of behaviours and actions in a crime that are, in a sense, typical of all those crimes. They may occur in two-thirds or more of cases. To some extent, they are the things that define the sort of crime you’re looking at. Then there are other actions that are rarer, less frequent, and these distinguish the different ‘themes’, which characterise subsets of crimes – and that is what identifies the salience.”

Canter gives the example of a rapist who breaks into his victims’ houses and takes things he can later sell on. “This is an individual who is indicating his criminal history as a burglar,” says Canter. “We would argue that this is someone who has decided – for all sorts of psychological reasons – that now he wants to steal sex as well. So we would say to police: ‘Don’t just search for people with a history of sexual or violent offences. Look for local burglars, they are more likely to be culprits in this case.’”

This is the consistency principle in action, and it applies to the geographical aspects of Canter’s work, too. “The first case I had any success with, I used very simple ideas about the locations of crimes to suggest where the offender may be based. It’s the same consistency idea that applies to people living in wealthy areas who won’t go to a poorer area to go shopping – so you can predict something about the characteristics of individuals based on where they shop.”

There are, sadly, relatively few of these cut-and-dried examples, says Canter. Human beings are never as simple as that. “One of the things we do know – and that you have to be alert to – is that offenders do change their behaviour. Although there is consistency in what we do as human beings, there is always some development and change that overlays on top of that.”

• Originally published in Impact Issue 5, April 2014. Click here for more information, or to subscribe.
• David Canter portrait courtesy of Olivier Hess