Around the time David Bernstein and Noah Isackson published their fascinating Chicago piece "Gangs and Politicians: An Unholy Alliance," I made a rough map of Chicago gang territory and homicides. Someone, or a couple people—I think it was @sethlavin and @superanne—suggested it'd be a good idea to correlate other data with homicides, particularly schools and socioeconomic data. I was reminded of this the other day, and decided to make an attempt.

The first data set is represented by the green and yellow dots: non-charter Chicago Public Schools by "performance policy level." It's a basic metric used by the CPS to calculate school performance (here's an example of how it's done), and is an element of evaluating whether a school will be closed: "Any school that has been on the lowest level of the district’s performance policy ('Level 3') for two consecutive years will be eligible, unless its graduation rate (for high schools) or percentage of students meeting state standards (for elementary schools) is above average in its geographic area."

There are three levels, 1-3, one representing the highest-performing schools, three representing the lowest. On the maps, green dots are Level One schools; yellow dots are Level Three. All the data comes from the city's Data Portal.

The red dots are 2012 homicides through June 26, using data compiled by RedEye's Tracy Swartz.

The blue regions are CPS socioeconomic tiers. CPS uses several criteria, from income to education, to determine the four tiers, which help determine selective-school placement. Open City Apps, where I got the dataset for the CPS tiers, has a good explanation. It's also just a good measure for the economic geography of the city.

Lighter represents lower socioeconomic tiers. Tier 1, on average, has a median family income of $29,928 and 4.8 percent of adults have a bachelor's or higher. For Tier 4, it's $104,434 and 33.4 percent.