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Geoprofiling Moves Into The Limelight
circletimessquare writes "Interesting and timely. A short piece at CNN talks about the software helping to track down the sniper currently terrorizing the Washington DC area. It was the doctoral thesis of a cop, Kim Rossmo, who developed it while walking the beat in Vancouver and reading about the hunting patterns of African lions. Googling, I found an older but deeper piece which mentions more of the tech behind the software, called Rigel. That led me to the website of ECRI, the company that makes Rigel. More good tech there."
It is possible to put a suppressor on a .223 rifle. This would make it much harder to identify, by sound, from where the shot originated. BTW, you don't have to "find" subsonic .223 rounds, you can just reload.
GEO-PROFILING: POTENT NEW POLICE TECHNIQUE
Cracking the Toughest Serial Criminal Cases
Dec. 31, 1998
By Jim Krane
SAN DIEGO (APBnews.com) -- Picture a small city in eastern Canada whose residents were rarely touched by violent crime. Then, startlingly, a serial rapist began attacking women, injecting a dose of fear into a normally tranquil community.
By the time the assailant sexually assaulted his 11th victim, police were desperate. They compiled a list of 300 possible suspects and prepared to conduct expensive, laborious DNA tests on each one, hoping to match DNA residue taken from victims.
Vancouver Police Detective Kim Rossmo
That's when Det. Kim Rossmo got a call.
Rossmo, a detective inspector with the Vancouver Police Department, developed an investigative technique called geographic profiling. Using geo-profiling, police try to trace a serial criminal to his home or workplace by computing distances with geographic clues he's left -- such as dead bodies, sites of attacks and other known locations the lawbreaker visited.
Rossmo explained geographic profiling to attendees at the International Association of Crime Analysts here recently, giving criminal analysts a window into one of law enforcement's newest and least-known investigative techniques.
Rossmo's methodology would come in handy on the serial rapist case and many others.
Valuable search tool
As part of his doctoral research at British Columbia's Simon Fraser University, Rossmo developed an algorithm -- a mathematical model of repeated calculations -- that targets serial criminals by the spatial patterns they produce.
Since then, Rossmo's algorithm has been computerized, allowing it to make hundreds of thousands of calculations that pinpoint a criminal's hideout within a fraction of the crime site area.
Priority: danger
Rossmo most often gets a call when a serial criminal is on the loose. Since many agencies -- in Canada, the United States and Europe -- seek his services simultaneously, Rossmo said he gauges which community is most at risk.
In the eastern Canadian sexual assault case -- Rossmo didn't want to divulge the location -- his geographic profile turned out to be remarkably accurate. With 300 suspects on their hands, the local police could only look forward to a lengthy period of laboratory testing.
The red peaks in this image identify the probable location of an offender's residence in Vancouver, British Columbia.
But Rossmo's geo-profiling technique helped the police get their man much more quickly. The Vancouver detective visited crime scenes, read reports, and talked to victims and investigators. He analyzed the data using his computerized algorithm and found a neighborhood hot spot to focus on.
Seventh time's a charm
Instead of hauling suspects in alphabetically by last name, police matched suspects' addresses against Rossmo's findings and tested those who lived nearest the hot spot's peak. The seventh suspect lawmen tested was a positive DNA match. Police arrested the man and cracked the case.
"If they didn't have geographic profile prioritization, they might've started with Archer and ended with Young," Rossmo said.
Lazy to a fault
Despite its complicated mathematical calculations, geographic profiling is based on a simple theory. Criminologists say most humans -- criminals included -- are inherently lazy. Just as a person will shop in the grocery store nearest his or her home, a predatory criminal usually picks his victims in familiar areas -- except for a small buffer zone around his home, says Rossmo.
Thus, when an arsonist sets a series of fires, police can estimate his whereabouts (usually a residence) by dumping the addresses of buildings burned into the computer and calculating the location most central to the crime scenes.
Crime as topography
In reality, Rossmo's crime-busting technique is more complex. He walks through crime scenes, conducts interviews and reads police reports. With years of investigative experience under his belt, Rossmo puts emphasis on certain locations based on his psychological assumptions about the quarry. At the same time, he discards or discounts other locations that he believes might skew his findings.
Rossmo then keys his data into the computer. The machine converts street addresses into latitudinal and longitudinal coordinates and creates a three-dimensional "jeopardy surface" or topographical model of the data. The jeopardy surface looks like a mountain range, with colored bands of peaks and valleys that show where the addresses converge -- the peaks -- and where they don't -- the valleys.
When Rossmo superimposes the jeopardy surface onto a street grid, the result isn't an exact map to the killer's house, but it's something close to it.
Method used in 80 cases
Since 1990, Rossmo has used his geo-profiling technique in more than 80 cases, representing 1,800 crime locations. He believes his work helped crack about half of those cases.
But Rossmo doesn't measure his success only by cases cleared. He's interested in geographic accuracy.
In cases where an arrest has been made, Rossmo's been able to estimate the location of the offender's home within the top five percent of the search area. That means, if police believe the offender lives somewhere within a 10-square-mile area, Rossmo can tell investigators which half-square-mile section to search.
In some cases, he's more accurate. In the Canadian rapist investigation described above, Rossmo's suspect lived within the first 2.2 percent of the area searched.
The more a criminal strikes, the more clues Rossmo can enter into his computer. Theoretically, that makes his predictions more accurate. But Rossmo's computer doesn't spit out a name and address. After the computer does its thing, Rossmo writes a report suggesting strategies for capture.
"It's the investigator that solves the case. Our role is to support him or her," Rossmo said.
Cops, meet Rigel
Rossmo's algorithm has been incorporated into a software program called Rigel, manufactured by the Vancouver firm Environmental Criminology Research Inc. (ECRI). Rossmo is a member of ECRI's board of directors and acts as the company's chief scientist.
Currently, Rigel runs only on a Sun Microsystems UltraSparc workstation. But ECRI is reprogramming it for use on Windows NT workstations and servers.
The software isn't cheap -- ECRI president Barry Dalziel priced a copy at $70,000, which includes some training and help with installation.
Rigel, emphasized Dalziel, isn't perfect. For best results, it should be used by a police investigator or crime analyst who undergoes a year of training, some of it under Rossmo's personal tutelage.
"If it sends them off on a wild goose chase, police investigators aren't likely to use the system again," said Dalziel.
It's a Canadian thing
Besides Rossmo's Vancouver Police, two other agencies have been trained in geographic profiling with Rigel: The Royal Canadian Mounted Police, Canada's national police force, and the Ontario Provincial Police. Rossmo said the British National Crime Faculty, another national law enforcement agency, will be certified in 1999.
No U.S. law enforcement agencies are on Rossmo's training list -- even though he's been invited to help crack dozens of cases in the States.
The real Robocop
If its geo-profiling uses weren't enough, Dalziel said investigators will be able to use a new version of Rigel to predict a serial criminal's next crimes, including dates and crime locations.
And cops will be able to predict and monitor the likely "hunting grounds" of paroled sex offenders by plotting past crime data and behavioral traits into Rigel, said Dalziel.
"Say there were crimes in that area that matched [a parolee's] M.O., his name would pop up," Dalziel said.
Jim Krane is APB News staff writer (jimk@apbnews.com).
I wear pants.
Kim Rossmo got his Ph.D. in criminology at SFU. The ideas in his thesis weren't just sudden inspiration -- they came from his many years as a police detective working on investigations, and from rigorous academic study and research.
Vancouver's Mayor had more police manpower directed towards a high profile pot shop in the area than the case of the 50 missing women. Rossmo's thesis was pooh-poohed and he was demoted and effectively run off the force.
The missing prostitute case continued to be a willfully low priority of the Vancouver police department until it recieved some publicy (including, I believe, being featured on "America's Most wanted" -- "Vancouver's a great place to be a serial killer -- cops cry '50 missing and all's well!'"
A little over 2 years later, they've charged a guy with killing 15 of those missing women, and are searching for more remains on his pig farm.
From what I've been able to piece together, he abused them, killed them, ran their bodies through a meat grinder (or branch grinder) and buried the ground-up bits on his farm.
In the meantime, Downtown Eastside residents who were formerly unwilling to report mysterious disappearances of friends to the cops have now brought the number of missing women into the 60 person range.
More info on the missing women case can be found on the CBC website.
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