The Hound of the Data Points

Gallien put surveillance on Comeaux. When Comeaux discarded a cigarette butt, agents recovered it and sent it to a lab -- and got their DNA hit. Gallien confronted Comeaux on the street and said quietly, Joe Friday-like, "It's over."



The case intrigued just about everyone who heard about it. The notion of a master geographic profiler conjured those classic film scenes in which detectives gaze at a trail of red pushpins in a big map, then guess where the killer will strike next.



In fact, though, it's just the opposite.



"Geographic profiling isn't about prediction," Rossmo says. "Efforts to predict the location of crimes don't show a lot of focus." Instead of pushing forward into an unknown future, Rossmo's method pulls back to an origin, to the time and place the crimes were hatched. A center.



"You know those sprinklers where the little metal thing hits the water stream and it sprays around in a circle?" Rossmo asks. "You could look at that and say, â€There's a good probability that the next drop of water will land within this ring,' but it'd be hard to know precisely where. If you took the sprinkler away, though, and I looked at the pattern of water, I could tell you where the sprinkler was."

Back in Vancouver, when Rossmo was heading up the world's first geographic profiling unit, a sign hanging on the office doorknob read "Bates Hotel: Please Make Up My Room." But the whimsy in his current office in D.C. is subtler: There's a replica Maltese Falcon on the windowsill; on the bookshelf, a copy of Burnt Bones, the Michael Slade novel in which Rossmo appears as a character.



When I arrive, he's scarfing down a bagel, which is breakfast and lunch and might just be dinner. His clothing palette suggests those spiritual mediums who hope to make themselves invisible to the phantom entities they're studying: black shoes, black slacks, black shirt. Impeccably shaved, with a cadaverous pallor, Rossmo is a wall with no handholds, a cipher. Even his accent is neutral (think Peter Jennings). If you ran into him at a bank or in an alley or at a crime scene you would never remember him later. (That said, a movie based on Rossmo's life is in the works, and a casting notice in a trade publication took an uncharitable crack at a description: "Hey, actors, if you're pudgy, 40ish and balding, maybe you'll get to play Canada's answer to Sherlock Holmes.")



The office is near Dupont Circle -- a ring within the bigger ring that is D.C. This is the headquarters of the Police Foundation, a private nonprofit agency that trains police departments in law enforcement strategies. Rossmo is director of research.



Phone messages cover the desk. They pile up while he is on the road, which is a lot of the time -- though not nearly as much as in his previous job, where he logged 100,000 miles a year as a kind of Holmesian brain for rent, dropping into investigations from England to Australia. Now when he helps solve crimes, it's on his own time.