How psychologists can assist in criminal investigations using offender profiling

Psychology is applied in law enforcement and the justice system in a variety of ways, some with more mass appeal than others. For example, most people are familiar with the concept of criminal profiling through television shows like “Criminal Minds” and “Mindhunter” as well as books like “The Silence of the Lambs”. It’s a classic story at this point: A serial killer is on the loose. The cops call on a brilliant Ph.D who combines Sherlock Holmes-level powers of observation with a keen knowledge of human nature. This psychologist studies the crime scenes, then uncannily describes the lifestyle and personality of an unidentified subject (unsub) in extraordinary detail. Lo and behold, the profile is an exact match for one of the nefarious murder suspects. The cops bring the suspect to the station, interrogate them based on lines of inquiry suggested by the profiler, and elicit a full confession. Case closed.

Licensed psychologists can play additional roles in policing, the courts, and criminal investigations. For example, a psychological autopsy might be performed after a suspicious death in order to determine whether the victim died by suicide. And a forensic therapist works with offenders within the legal system to assess their mental competency, evaluate their criminal responsibility, and determine whether they pose a risk to society. Psychologists serve as expert witnesses in trials all the time, testifying about a defendant’s state of mind or something more general, like the infamous unreliability of eyewitness accounts and why people confess to crimes they didn’t commit. 

But criminal profiling (also called criminal investigative analysis) tends to capture more popular interest than any of these jobs. Investigative psychology seems like a tantalizing blend of true crime, behavioral science, psychic powers, and the Barnum effect (one’s tendency to identify with vague personality traits). Let’s take a look at a few times where offender profiles helped solve violent crimes—and where they didn’t. Is it possible to work out who offenders are by the psychological clues they leave behind? [Warning: violent crimes discussed ahead.]

True Stories of Psychology Cracking Cases

There are plenty of compelling stories about criminal profiles leading to the capture of serial killers. In fact, criminal profiling seems best suited for lurid crimes: murders, sexual assault, arson, terrorism, and hostage situations. Forensic psychology is a dark business to be in, but it’s been known to achieve results. Here are some famous cases of investigators using psychology to nail violent offenders: 

Howard Teten nails David Meirhofer. After a little girl was kidnapped and murdered while camping with her family in Montana in 1973, Howard Teten, the cofounder of the Behavioral Science Unit at the Federal Bureau of Investigation (FBI), developed an offender profile that narrowed down the suspects to David Meirhofer, who was a white local man with a background in telecom, just as Teten’s profile indicated.

John Douglas nails the “Trailside Killer” David Carpenter. After numerous murders of women along San Francisco hiking trails in 1979-80, authorities contacted FBI profiler John Douglas. Douglas developed a profile of the unsub, specifying that he would have a speech impediment. Carpenter, one of the suspects, had a stutter. He remains on death row in San Quentin. 

David Canter nails John Duffy. When numerous women were killed in London between 1985 and 1986, the authorities asked geographical psychologist David Canter for help. He developed a geographical profile on where the offender might live, but he also theorized that the killer was right-handed, knew about the railway system, and had a criminal record. This information was instrumental in the capture of ex-railway carpenter John Duffy and his accomplice David Mulcahy.

The Federal Bureau of Investigation (FBI) nails Arthur Shawcross. After the murder of 11 women in upstate New York between 1988 and 1989, the FBI’s Behavioral Analysis Unit (BAU) developed a profile of the unsub that posited he would revisit his deceased victims. This led to surveillance of the latest crime scene and the capture of Arthur Shawcross, who was reliving the pleasure of his murder from a bridge near his dead victim.  

Mary Ellen O’Toole nails the “Green River Killer” Gary Ridgway. In 2003 veteran FBI profiler Mary Ellen O’Toole used psychological influence to coax Gary Ridgway into confessing to 48 murders, making him the second most prolific serial killer documented in the US. (O’Toole also wrote a book about how people can often be fooled by their gut instincts, especially since she believes that some of the most dangerous offenders seem perfectly normal on the surface.) 

Criticism of Criminal Profiling

Not everyone celebrates criminal profiling as a science, and this may be in part because there are huge disparities in how psychologists and criminologists develop their profiles. Some of them use advanced statistical analysis, and others rely more on intuition and educated guesswork. 

Another source of criticism is the lack of good data about how helpful these profiles are within law enforcement agencies. Critics say that stories of criminal profiling tend to be anecdotal and focused on what was proved right rather than what was proved wrong. It seems as if for every suspect pool that’s narrowed down by a qualified psychologist, another psychologist misses the mark. For example, no one guessed that the 2002 Beltway sniper was in fact a 41-year-old black man and his 17-year-old accomplice, driving a blue sedan. Profilers had posited that the offender was a disgruntled white man in his 20s or 30s driving a white van. 

Criminal profilers also might assume, rightly or wrongly, that a) peoples’ behavior is consistent, and b) that similar behavior is driven by similar characters/personalities (known as the homology assumption). As an example of the latter, famous FBI profiler Robert Ressler interviewed convicted serial killers at length to come up with a typology of the criminal mind. He determined that certain backgrounds were associated with certain antisocial behaviors. In addition, FBI profiler Roy Hazelwood concluded that violent offenders would consistently exhibit organized or disorganized behaviors. But crimes can be a mixture, and they’re influenced by situational factors as well as personality. And profilers Robert Keppel and Richard Walter concluded that serial sexual homicides were perpetrated by four types of motives: power-assertive, power-reassurance, anger-retaliatory, or anger-excitation. Can human behavior really be classified so neatly? 

In a 2007 New Yorker article, Malcolm Gladwell uses the case of “Mad Bomber” George Metesky, a serial bomber in Manhattan who was captured in 1956, to illustrate how he thinks criminal profilers use simplistic psychology and the same ambiguous language that astrologers employ, giving them more authority than they perhaps deserve. James Brussell, author of “Casebook of a Crime Psychiatrist”, was the man who predicted that the serial bomber would be wearing a buttoned-up double-breasted suit when he was arrested (which is what Metesky changed into after the cops arrived at his door). But Gladwell points out that the case’s true hero was Alice Kelly, who first flagged Metesky’s name in Con Edison’s personnel files (Metesky was a disgruntled former ConEd employee). 

Gladwell thinks that a profiler’s language can be so vague, contradictory, and unverifiable that it can support virtually any personality. For example, a profiler can use the following linguistic tricks so their predictions seem correct no matter who’s arrested:

• The rainbow ruse, which grants someone one character trait and its complete opposite.
• Fuzzy facts, which leave room for specifics to be filled in later.
• Vanishing negatives, which ask questions in a negative, then disappear the negative if a subject answers positively. For example, “You don’t work at the grocery store, do you?” Individual answers no. “Right, I thought not.”

And Gladwell cited one study that seemed to prove the Barnum effect, where police personnel read two contradictory criminal profiles after an arrest and declared them both to be accurate and useful. 

The Future of Criminal Profiling

In defense of criminal profiling, one might say that police sketches can be vague as well, but every once in a while they can help nab a suspect. Perhaps investigators should use every (ethical) tool in their toolbox to catch offenders, especially for heinous crimes.

Detectives have always used psychological profiling to assess criminal behavior and solve crimes, just with a top-down approach rather than a bottom-up approach. For example, a detective might suspect an ex-husband of murder because he was motivated by jealousy. In both cases, errors can be made when you lean into one suspect or one theory to the exclusion of other leads. But at the very least, psychology can be translated usefully into practical operations, like when a suspect’s profile suggests a line of questioning during an interrogation. And sometimes serial criminals do behave consistently, enabling profilers to link their crimes.

One researcher called criminal profiling “an art with the potential of becoming a science”. Investigative analysis is becoming more rigorous all the time. And if it saves even a single life or spares someone a trauma, it’s definitely worth pursuing.