“If you want to understand the spatial patterns of a criminal you probably wouldn’t be far off if you look at the spatial patterns of a shopper.”
We are — even the felonious among us — creatures of habit. Dr. Kim Rossmo of Texas State University, who studies the geography of crime, has found that criminals tend to behave according to reliable geographic patterns. Rossmo’s formula (and that’s not just a turn of phrase — there is something called “Rossmo’s formula”) is used to explain how serial thieves, rapists and other criminals commit their offenses at a close-but-not-too-close distance from their home. When this geospatial analysis is combined with more traditional evidence, it can help narrow down a list of suspects.
Now, Rossmo thinks his methods have helped identify the long-hidden identity of the street artist Banksy. A yearlong investigation by the Daily Mail concluded that Banksy is a man named Robin Gunningham. We don’t know much about Gunningham. He’s, 42, he’s from Bristol, England, he went to a Catholic prep school.1 Rossmo’s analysis adds more credence to that theory.
His model analyzes clusters of criminal activity (in this case, Banksy’s graffiti) and calculates the probability that the offender would be working from a given geographic source (e.g., their home). The modeling by Rossmo and his colleagues honed in on several locations in Bristol and London — all of which aligned with known addresses for Robin Gunningham.
On this week’s podcast, Rossmo discusses his work, how he tracked Banksy, and the way his model can help explain all sorts of behavior. Turns out, sharks tend to hunt in the same way Banksy tends to draw.
Stream or download the full episode above, or subscribe using your favorite podcast app. Here are some excerpts from the conversation.
Criminal behavior is human behavior
Dr. Kim Rossmo: Criminals are not fundamentally different than the rest of us. In fact, that’s one of the truisms — criminals, for 95 percent of their life, behave just the same as anyone else does.
So if someone is going out to commit an offense, they want to operate in an area of familiarity, because they are engaged in risky behavior. But at the same time, they don’t want to commit a crime on their own doorstep, in most cases. And remember, we’re dealing with probabilities here, not certainties. So that means that nothing is 100 percent, but we can describe with a probability distribution.
Jody Avirgan: But why would an artist behave in the same way as some other criminals? Wouldn’t an artist, who wants his work to be as visible as possible, and knows that people are on the lookout for him, break from that comfortable geographic pattern and be a little less predictable?
Rossmo: Think about where you live. If I were to ask you, “What’s going on two miles from where you live?” You probably have no idea. You’d have a few select spots that you know of, but most people don’t have a great knowledge beyond a few blocks from their home. So [Banksy] could get a lot of anonymity very, very quickly. Plus, he’s got to choose sites. So if he’s already got a general knowledge of an area, he has a better idea of where to find locations.
The bottom line is graffiti artists, burglars, car thieves … many of these individuals behave in the same fashion in terms of their search for targets and their hunt for crime opportunities.
How wide is a criminal’s comfort zone
Avirgan: You mentioned that patterns can be different kinds of crimes or criminals. But in the case of Banksy, or another example, are you saying that someone is comfortable when they go two blocks from their home, or two miles from their home? How big are these circles and patterns?
Rossmo: The research in what’s called “journey-to-crime” finds that most offenders commit their crimes one to two miles from their home. It varies for a number of factors: the age of the offender, or the gender, the type of crime, but we would say that in most cases the crimes are close, and they are closer for violent crimes than for property crimes.
Avirgan: Do those patterns differ across different cultures?
Rossmo: To a certain extent, you’ll see things that are specific in certain places. For example, I worked on a serial murder case in Johannesburg, South Africa. They have these big mine dumps, hills that are in the middle of the city. And the offender was using those for observation points.
If you go to the Netherlands, many rapists use bicycles, because that’s just how most people travel. So it’s less about the culture than about the actual environment of the city, and whether the offender is walking, taking the bus, driving. If you’re dealing with crimes in Los Angeles, almost everyone drives, so you have to factor in the freeway system.
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