The Chicago Police Department is using a tool academics call “network analysis” to map the relationships among Chicago's 14,000 most active gang members, reports Governing. It's ranking how likely those people are to be involved in a homicide, either as victims or offenders. Police have discovered that cities don't so much have “hot spots” as “hot people.” That finding is transforming the way the police do business in Chicago and has significant implications for how other cities should be policed. The idea is closely connected to the department's enthusiastic embrace of network or link analysis, an embrace that began with the work of an unorthodox Chicago-born sociologist, Andrew Papachristos.
Papachristos grew up in the 1980s on the city's North Side. His father, a Greek immigrant, ran a neighborhood diner that refused to pay gangs for protection and eventually was torched. At the University of Chicago, he conducted ethnographic studies and concluded that attempts to explain urban violence in terms of factors such as poverty and race did a disservice to many of the people in the highest-crime communities. Most residents of even the poorest neighborhoods didn't kill or commit violent crimes. Most gang members didn't either. But when they did, it was often as members of a group. “These groups have agency. They have structure. And it's not random. In fact, the big thing there was that they're inheritable,” says Papachristos. That is, gangs don't necessarily know why, but generation after generation, they shoot one another.