Studies is working on—tracking the relationship between repeat offenders, victims, and witnesses, and trying to figure how to keep them from showing up in one another’s police reports. The diagram Martin projected onto the screen depicted a woman who was arrested for assaulting her daughter and showed up in separate police reports as a witness to two other assaults, which in turn linked her to both the victim and perpetrator in still more assaults, including a man who is a co-offender in a family neglect case.
“Repeat offenders are still committing many of the crimes, even after our crime rate has gone down so much,” Martin told the group. “This software will allow us to link all of the perpetrators in a network to see which ones are involved in the most crimes. The live network analysis will also allow us to see who’s moving up in the criminal world.”
That news met with grunts of approval from around the table and, after reviewing block club concerns (lack of working street lights, loitering), and briefing the group on the progress of a stolen-car transaction the department was tracking (a satellite had monitored the car overnight), the CompStat meeting was adjourned.
“Every police department has something,” Martin explained later in his office when asked about the role technology now plays in policing. “At minimum, they’ll talk about persistent problems at roll call, and maybe the chief is involved. But as you get to larger cities, these are big geographical areas with lots of people. Police departments collect so much information at traffic stops, in crime reports, from calls to dispatch, but it’s only in the past 10 years that great leaps in technology have helped police departments exponentially. It’s amazing how far we’ve come.”
Martin first got into the field in 1995, the very early (and primitive) years of crime mapping. Back then, his department had to spend $1,000 on software and then put him through training before he could use it.
“There was no online webinar,” Martin said. “I had to go to class for a week to learn how to use it.”
Martin describes the Detroit Police Department’s crime mapping of the time as being limited to one sergeant who decided to dedicate the last years of his career to
