Associate Professor of Criminal Justice, Michigan State University
- Homicide clusters were present before clusters of firearm-related homicides, indicating sources other than firearms caused homicide to diffuse in Newark, New Jersey.
- Homicide clusters related to gang activity appeared in different wards, but the data didn’t indicate whether the gangs moved into or evolved out of those wards.
- Certain wards considered to be “immune” to homicide had low percentages of African American residents but were the most diverse wards in the state.
In the article, “Homicide as Infectious Disease: Using Public Health Methods to Investigate the Diffusion of Homicide,” Zeoli and her co-authors examine the diffusion of homicide crimes from the perspective of a public health issue. Diffusion describes the movement of phenomena from its origin across areas. The elements of diffusion are: 1) source of phenomena (gangs, firearms, etc), 2) mode of transmission (youth gangs, drugs, fear), 3) population that is vulnerable to phenomena (minority males in low-income areas). To conduct their study, the researchers examined the homicide rate in Newark, New Jersey, which has historically had a homicide rate three times the national average. They used data from Newark Police Department’s Homicide Unit from 1982 to 2008 to track long and short term trends over time. The results showed the homicide clusters were present before clusters of firearm-related homicides, indicating sources other than firearms caused homicide to diffuse. The data also showed homicide clusters related to gang activity appeared in the central and west wards as well as the public housing sites in the east ward. The data doesn’t indicate whether gangs moved into or evolved out of these areas. The most notable finding was that certain wards considered to be “immune” to homicide had low percentages of African American residents but were the most diverse wards in the state. The authors concluded that racial segregation in wards compounds the already vulnerable wards to the diffusion of homicide.