Murder is like a disease. No, really.
With a homicide rate historically more than three times greater than the rest of the United States, Newark, N.J., isn’t a great vacation spot. But it’s a great place for a murder study.
Led by April Zeoli, an assistant professor of criminal justice, a group of researchers at Michigan State University tracked homicides around Newark from 1982 to 2008, using analytic software typically used by medical researchers to track the spread of diseases. They found that “homicide clusters” in Newark, as researchers called them, spread and move throughout a city much the same way diseases do. Murders, in other words, did not surface randomly—they began in the city center and moved in “diffusion-like processes” across the city.
The study also found that the there were areas of Newark that, despite being beset by violence on all sides, remained almost completely immune to the surrounding trends over the entire course of the 26 years studied. Despite the longitudinal nature of the study, Zeoli notes in a press release that the analytic software can be employed in real time, so that police might potentially identify problem areas as they are emerging—or perhaps, one imagines, before they emerge. The research is due to be published in a forthcoming issue of the journal Justice Quarterly.
But why does violence spread this way? And why are some areas almost more immune than others? The answers are complicated and uncertain. But some clues emerge from the data.