Thursday, June 26, 2008

The Impact of Maps on Crime - Atlantic Montly Shows How Sharing Crime Data Leads to Action

In the newest July 2008 issue of Atlantic Monthly, contributing editor Hanna Rosin tackles the question "Why is crime rising in so many mid-sized American cities?"

The answer was discovered when the police shared their data with someone who created a visual map (seen in the print magazine) of the problem. The North Memphis police shared their crime data with University of Memphis criminologist Richard Janikowski, and he turned that data into an answer.

He’d built up enough trust with the police to get them to send him daily crime and arrest reports, including addresses and types of crime. He began mapping all violent and property crimes, block by block, across the city. “These cops on the streets were saying that crime patterns are changing,” he said, so he wanted to look into it.

By sharing their data, the police were able to let a private citizen create a tool for them, and obtain new information in the process. It was a win-win situation, and a great reason for government data transparency.

When his map was complete, a clear if strangely shaped pattern emerged... Hot spots had proliferated since the mid-1990s, and little islands of crime had sprung up where none had existed before, dotting the map all around the city...

What he came up with ended up showing a correlation between new Section8 housing and crime, a very unpopular and controversial result, and something not intuitively discoverable.

Janikowski merged his computer map of crime patterns with [a] map of Section8 rentals... On the merged map, dense violent-crime areas are shaded dark blue, and Section8 addresses are represented by little red dots. All of the dark-blue areas are covered in little red dots, like bursts of gunfire. The rest of the city has almost no dots.

Most of the article deals with the implication of this outcome and how to handle it, and the complex socio-economic issues it raises.

On a side note, our Louisville police chief also got involved, and a University of Louisville professor was looking at these patterns too.

The “Gathering Storm” report that worried over an upcoming epidemic of violence was inspired by a call from the police chief of Louisville, Kentucky, who’d seen crime rising regionally and wondered what was going on. Simultaneously, the University of Louisville criminologist Geetha Suresh was tracking local patterns of violent crime.
It's great to see such a terrific outcome come from the sharing of public data and is just the sort of thing the OMG Standard is trying to accomplish. A success story, but it only came because of the years of trust that Janikowski garnered by working with the local police full time. Months or years could have been shaved off the timeline if the data was made easily available to the public from the beginning.

3 comments:

Justin Massa said...

The article in The Atlantic is a very interesting example of data sharing. I think Michael is right that it shows the power of maps, but the conclusions that the author and the researchers cited reach correlating crime and Housing Choice Vouchers highlight what can go awry with maps. Rather than looking to understand why Housing Choice Voucher holders end up living in a narrow set of neighborhoods, the article simply blames them for increases in crime rates in the neighborhoods where they do end up living. The story ignores the harsh realities of race, familial status, and - legal in Memphis - source of income discrimination. Maps are powerful tools, but only with the appropriate context can they be powerful tools for social change.

Michael Schnuerle said...

Justin, welcome to the blog. Great comment too, especially coming from an expert on housing for low-income citizens. I agree with your thoughts too.

The maps offer a starting point for conversation about the cause of a problem, or offer a new way to look at an issue. It is easy to jump to the wrong conclusion by not looking at the whole picture. I also thought the story was a little too focused on a simple cause-effect answer, rather than dealing with all the other possible causes you listed.

I see maps like statistics; they can be used to prove any point. In fact, they have a long history of being abused by cartographers. Initial world projections intentionally exaggerated the size of Europe and diminished the size of Africa. Maps are great tools, but must be treated with skepticism, like anything else.

Drupal Web Developer said...

On a side note, our Louisville police chief also got involved, and a University of Louisville professor was looking at these patterns too., so these are the solution from this..