Longtime readers of the Director's Desk have been bored stiff from time to time with my ruminations about such topics as evidenced-based policing, situational crime prevention, and the like. Of particular interest to me is a phenomenon that is at the heart of a lot of good police work: digging into crime where it actually occurs--particularly impacted neighborhoods, blocks with pernicious problems, specific addresses with repeat offenses, even an individual apartment.You will find lots of examples here in my blog about problem-oriented policing strategies that are targeted at these micro-places.
A friend is the co-investigator on several research projects that have involved crime hot spots. One of these that caught my attention last year was a study of juvenile crime in Seattle. The reserarchers, Drs. David Weisburd, Elizabeth Groff, and Nancy Morris, found that a huge percentage of juvenile crime occurs on a very small percentage of the block faces in Seattle (a block face is both side of one street, between the two adjacent intersections--like the 1500 block of S. 9th Street.)
I've been meaning to look at this in Lincoln for some time, and I got motivated yesterday to do so, a job that took about 15 minutes to set in motion, and ran on my computer while I was away at lunch. Here's my method: I took all the crimes reported to LPD in 2012 (21,153 total), and joined those points to the nearest street segment. Street segments in our geographic information system are essentially the equivalent of the block faces studied by Dr. Weisburd, et al. in Seattle. I then summarized the crimes by street segment, and joined the results back into the streets layer. My result was a GIS layer of streets, where each segment also has a COUNT field that is the sum of the 2012 crimes along that segment. Here are the results:
There were 13,771 total street segments in the City of Lincoln. Of those, 7,481 (54%) had no crime at all in 2012. Moreover, 81% of all the crime (14,149 offenses) occurred on only 5% of the street segments (689 segments). The top 1% of the street segments (138 segments) accounted for 7,148 crimes--41% of the total.
These data are consistent with other studies, and demonstrate something very clear: crime is intensely concentrated at these very local micro-places. Police efforts focused on intervening in the conditions and preventing crime at individual premises on those blocks where crime is concentrated are far more likely to be effective than driving around aimlessly burning fossil fuel (or as we call it in policing, "routine patrol").
Here's a snapshot of the 5% of the street segments in Lincoln where 81% of the crimes occurred in 2012.