Chicago’s shootings ‘contagious’ like a disease, new study says

A 43-year-old man was shot to death outside Express Grill near South Halsted and West 18th streets in May. | Ashlee Rezin/Sun-Times

Chicago’s rampant violence is contagious and should be treated like a disease, according to a study published Tuesday in JAMA Internal Medicine.

Researchers focused on a network of about 138,000 people in Chicago — including about 9,800 gunshot victims — between 2006 and 2014. The network was comprised of people who’ve been arrested with someone else.

Shooting victims were almost twice as likely as non-victims to have associated with another gunshot victim in the network, the study found. The average time that elapsed between two associates getting shot was just 125 days, according to the study by Andrew Papachristos of Yale University and Ben Green and Thibaut Horel of Harvard University.

Their study said gun violence in Chicago and other cities like Newark, N.J., and Boston “follows an epidemic-like process of social contagion that is transmitted through networks by social interactions.”

The researchers said violence-prevention programs in Chicago and across the country should take a “public-health approach” to dealing with people in dangerous networks.

Being in a violent social network poses an even greater risk than demographic factors like race, age, sex and living in a high-crime neighborhood, the study found.

“All those things still matter,” said Papachristos, a native Chicagoan and an expert on street gangs here. “This has given us a way to fine-tune it. It’s a roadmap to look at risk. We’re saying, ‘Here is someone who is at risk to get shot. What can we do?’ ”

Assoc. Yale Prof. Andrew Papachristos | File photo

Groups like CeaseFire Illinois that seek to prevent violence by interrupting conflicts could use such social network analysis to narrow their focus, the researchers said.

And hospital-based violence intervention programs could use such research to extend their services beyond emergency rooms to others at risk of becoming gunshot victims, according to the researchers.

Since 2010, the Chicago Police Department has been using social-network research to fight crime. Under the “custom notification” program, commanders and community leaders have been visiting the homes of at-risk people to warn them to get out of their violent lifestyles. The department reaches out to people likely to become victims or shooters.

Papachristos and his colleagues said violence-prevention efforts should center on the likely victims and not on the potential shooters — and they said law enforcement is only one solution to the problem.

“Concerted efforts should focus on making gun violence prevention efforts [victim]-focused rather than offender-focused by prioritizing the health and safety of those in harm’s way, the study said.

“The individuals identified in our study are not in contact just with the criminal justice system: they are also deeply embedded with the public health, educational, housing and other governmental systems.”

Papachristos added, “We are trying to ensure victims are front and center, and not some afterthought.” Pointing to the large number of murders in Chicago in 2016, he said, “If you want to drive that number down, we have to focus on saving lives.”

In an accompanying article in JAMA Internal Medicine, Charles Branas, a professor at the University of Pennsylvania, responded to the study, saying that “a sole focus on ‘hot people’ as part of firearm violence prevention programs, although potentially fruitful in the short-term, may not produce sustained success.”

“Fixing up abandoned buildings or greening vacant lots can often address the underlying reasons that allow potential offenders, victims, and firearms to come together in the first place. There is now evidence . . . in Chicago and other cities, showing the effectiveness and cost-benefits of programs to remediate urban blight in significantly decreasing firearm violence.”

Previously from Chicago News