Murder is contagious and may spread like the flu, new research suggests. The researchers relied on the same techniques public-health officials use to track the spread of diseases, but applied them to the spread of homicide in Newark, N.J., over a 26-year span from 1982 to 2008.

And just as in other epidemics, certain neighborhoods were more susceptible than others. Diverse, immigrant-rich communities looked to be protected against homicide’s spread in the research, while the poorest neighborhoods were more vulnerable. These findings, detailed in a forthcoming issue of the journal Justice Quarterly, suggest communities could inoculate themselves against murder waves by addressing the underlying risk factors, said study co-author April Zeoli.