Police patrolling and predictive crime stopping

Many of us have seen the movie "Minority Report," based on the idea that murders can be prevented, by predicting their happening and arresting the perpetrator, based on his/her intentions.

Technology Review reports in "L.A. Cops Embrace Crime-Predicting Algorithm: Burglary reports dropped after officers began taking patrol orders from computers," on a test of a software modeling program that creates "heat maps" of areas likely to experience burglaries and car break-ins, based on past experience.

From the article:

The company tested on previous data whether crimes occurred more frequently in the areas identified by the software, compared to boxes sketched by crime analysts. Between November 2011 and April 2012, in the crime-plagued Foothill district, the software predicted crime six times better than randomly placed boxes. Human crime analysts' boxes were only three times better than the random boxes, according to Brantingham.


But whether the algorithm is right or wrong, it tends to reduce bureaucratic procedures and thus keep officers on the street, which by itself helps. Where police used to sit in daily meetings to plan where to patrol, they can now spend more time actually out on patrol, since the computer's doing the planning. And if they do spook a would-be burglar into abandoning his plan, it means even more time on patrol, because the officer doesn't have to leave his beat to process the suspect. "I don't have them back writing a burglary report. I can have them have more minutes out on the mission. It is what we see happening," Malinowski said.

One of the advantages of this kind of system is that it directs personnel resources objectively, and provides a way for police departments to counter political choices about force planning in response to resident perceptions that often aren't correct.