The Hound of the Data Points

The phone rings. Rossmo is quiet on the receiver for 30 seconds. "Oh wow," he says finally. "Do they believe these are linked?" A breaking case, a series of rapes and sexual assaults in Europe: The FBI has suggested parachuting Rossmo in. He explains to the agent on the line how it usually works: He prefers to go with other profilers, sharing ideas. He's going to need to be briefed, and he's going to need maps of the area.



The Lafayette rape case was just one among a series of events that have slowly built the brand of Rossmo. Five years ago, as prostitutes began disappearing from Vancouver's skid row at an epidemic rate, Rossmo was the first to suggest a serial killer might be at work. (He was ignored. Since then, the remains of some of those women have turned up on the property of a local pig farmer who stands charged with 15 counts of murder.) Two years ago, Interpol gave its stamp to geographic profiling; the international police agency now recommends the technique, where appropriate, to help focus DNA gathering from suspects. And last year the International Criminal Investigative Analysis Fellowship, the de facto league of psychological profilers, accepted geographic profilers into its ranks.



Indeed, the old guard from Quantico -- not known for suffering fools -- are among Rossmo's fans.
"We have a mutual respect," says Roy Hazelwood, the famed serial crimes investigator and former instructor at the FBI academy, who worked with Rossmo on the "Alphabet Murders," a cold case re-opened at the behest of the Discovery Channel.



But it was in October, when Montgomery County police captain Barney Forsythe called Rossmo about a killing rampage -- one that would become a daily deathwatch in the D.C. area covered by media around the world -- that "geographic profiling" became a dinnertime buzz phrase.

The mathematical equation at the heart of geographic profiling came to Rossmo in a flash a little south of Tokyo as he rode the bullet train toward Nagoya one day in 1991. Gazing out the train window, into the slow strobe of the whizzing countryside, something began to gel.



Like Archimedes in his tub, Rossmo was sitting on an idea years in incubation. While studying criminology at Simon Fraser University in Burnaby, B.C., Rossmo had been mentored by the respected husband-and-wife team of Paul and Patricia Brantingham, who had already made big strides in crime-pattern theory. They'd taken two existing concepts in criminology and combined them to form what they hoped would be an effective predictive model. The first was the notion that offenders left "buffer zones" around their homes in which they avoided committing crimes, to protect their anonymity. The second was something called "distance decay," a mathematical function that described the way offenders journey to commit crimes, venturing farther from home the bigger the potential payoff (which often means the more violent the act).



But the Brantinghams hadn't cracked the nut. They hadn't found the magic algorithm. What they had done was prepare the ground for an ambitious successor. Someone, say, who was such a math whiz that he asked to take his Grade 12 math final in the second week of class -- and whose perfect score excused him for the year. Someone who knew crime patterns from two sides, having first walked the beat on Vancouver's rugged skid row and then steeped himself in theory on the way to becoming Canada's first cop with a Ph.D. Someone smart enough to figure out that if you just flipped his mentors' logic, you could calculate where a killer lived from where he traveled, rather than the other way around.