In 1986 when criminal profiling —a behavioral and investigative technique developed by the FBI Academy to help investigators find killers—was just getting its start, John Douglas and Robert Ressler, together with Ann W. Burgess and Carol R. Hartman, cited Agatha Christie’s Hercule Poirot as the inspiration for their endeavor. They begin that landmark publication with the following citation:
I looked at him and grinned… “All right then,” I said. “Give us the answer to the problems – if you know it.”
“But of course I know it.”
Hardcastle stared at him incredulously… “Excuse me. Monsieur Poirot, you claim that you know who killed three people. And why?…All you mean is that you have a hunch.”
“I will not quarrel with you over a word…Come now. Inspector. I know – really know…I perceive you are still sceptic. But first let me say this. To be sure means that when the right solution is reached, everything falls into place. You perceive that in no other way could things have happened.”
Christie. A. (1963). The Clocks (pp. 227-228). New York: Pocket Books.
This is not a mere reiteration of Sherlock Holmes’s famous dictum: Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth as Hunter and Ressler make clear in their very next paragraph.
The ability of Hercule Poirot to solve a crime by describing the perpetrator is a skill shared by the expert investigative profiler. Evidence speaks its own language of patterns and sequences that can reveal the offender’s behavioral characteristics. Like Poirot, the profiler can say, “I know who he must be.”
“Criminal Profiling from Crime Scene Analysis,” Behavioral Science & the Law, Vol. 4, pp. 401-402 (1986)
Nor is this a matter of gathering more evidence. It is a matter of psychology, as Poirot tells Hastings in Agatha Christie’s Dumb Witness: Hercule Poirot Investigates.
“You have the mistaken idea implanted in your head that a detective is necessarily a man who puts on a false beard and hides behind a pillar! The false beard, it is vieux jeu, and shadowing is only done by the lowest branch of my profession. The Hercule Poirots, my friend, need only to sit back in a chair and think.”
Thus, from a close examination of the crime scene where particular attention is paid to the way in which the victim was murdered together with an analysis of the characteristics of the victim—prostitute, blond, young, old—or multiple analyses of crime scenes and victims, it is possible for a trained profiler to “use the little gray cells” as Poirot does to determine the psychological makeup—the main personality characteristics—of the killer or killers.
Profiling by the FBI does not provide police detectives with the specific identity of the killer. FBI profilers do not examine suspect lists so as not to bias their results. Rather, criminal profiling gives the police a psychological sketch of the main personality characteristics of the person who committed the crime, his or her likely subsequent behavior, and the likely triggering event or stimulus for the crime, and in some cases the killer’s motive. As a law enforcement tool, it is used to narrow the field of investigation and can be used by detectives to rule out suspects.
Profiling has been used successfully in hostage negations and in the capture of arsonists, serial killers, and child rapists.