Tuesday, July 28, 2009

Mapping Murder

I browsing Adrian McKinty’s blog at the weekend and he had a post about an interactive map of homicide in New York. His post mainly concerns the fact that 88 percent of the victims are black or Hispanic and how this reality isn’t reflected in TV cop shows. What I found interesting though was the map itself and the geography of the murders and how the deaths were mapped with respect to the race, sex and age of the victim and perpetrator, weapon used, year committed, and so on, to reveal distinctive patterns concerning the social and racial make-up of the city.

The map below clearly shows a geography to the race/ethnicity of the victim, with most of the victims in Brooklyn black; a strong concentration of Hispanic deaths (in Jackson Heights) and a small cluster of Asian deaths (in Flushing) in Queens; a mix of black and Hispanic victims in Harlem and the Bronx; and a fairly even mix of white, black and Hispanic murders in Lower Manhattan.

This kind of mapping is very common in just about every police force in the Western world at this stage, with each divisional command having its own GIS (Geographic Information System) intelligence unit that maps all crimes with its associated data (crime type, victim and perpetrator details, weapon, drug type, etc) and seeks to understand the patterns in order to help solve cases, allocate police resources, target crime hotspots, help profilers, calculate emergency response routes, and so on.

The three maps below are generated using a commercial GIS crime package – Mapitude – and plot the location of sex offenders vis-à-vis school location; motor theft hotspots; and change in the property crime rate over time (clicking on the image should enlarge it).

Given I’m fascinated by maps, as and when I come across some interesting ones relating to crime, I’ll add them to the blog. If anyone has any pointers to other interesting crime maps I would be delighted to receive them.


Dorte H said...

What a fine combination of two of your interests! If I should need advice on mapping, I certainly know where to go now. Maps and graphs are often very clear ways of getting a point across I think.

By the way, I have something for you on my blog.

Uriah Robinson said...

I am fascinated by maps and the interesting figures you quote. It reminds me of staying with friends in a rural 88% white county in Pennsylvania and watching the local police load up enough firepower into the trunk of their car to invade a small country. I was then told by our friends that only one murder [wife shooting husband] had occurred in that county in the last year.

Anonymous said...

A minor typo in an otherwise excellent post: The software is actually the "Maptitude" Mapping software (not Mapitude)