People who are threatened with firearms as adolescents are more than three times as likely to commit gun violence when they grow up in comparison to other at-risk youth, according to a new first-of-its-kind study using nearly two decades of data from Chicago. 

The paper, published Thursday in the medical journal JAMA Network Open, is the first to examine the association between adolescent exposure to firearms and adult gun violence on a longitudinal basis, meaning the researchers followed and repeatedly observed the same group of individuals from adolescence into adulthood. 

“The most shocking finding is that having been victimized as a kid makes you more likely to perpetrate firearm violence as an adult,” said lead author and principal investigator Linda Teplin, director of the Health Disparities and Public Policy Program at Northwestern University’s School of Medicine. “We just didn’t expect that.”

The researchers also found that people who had been injured by guns as adolescents were 2.4 times more likely to perpetuate gun violence as adults. 

While researchers had theorized that there may be a relationship between youth gun victimization and adult violence, Teplin said the empirical literature around the topic was “wide open” when she started the study. 

“People have hypothesized relationships” about this, she said. “But there haven’t been any sound empirical studies.” 

In order to research the issue longitudinally, Teplin and her six co-authors selected a random sample of 1,829 young people who had been arrested, detained and were awaiting adjudication or disposition of their case at Cook County Juvenile Temporary Detention Center in Chicago from 1995 to 1998. 

The researchers then periodically conducted follow-up interviews with the individuals for the next 16 years, conducting nearly 18,000 interviews through 2015. 

The subjects were disproportionately poor and from racial minority groups in comparison to young people in Chicago as a whole, the researchers said. Of the sample, 85% of males and 63% of females had been involved with firearms in some form as adolescents, reporting they had access to guns, had used guns themselves or had been threatened by guns. 

In adulthood, 41.3% of the men and 10.5% of the women had perpetrated firearm violence.

The researchers said their striking findings came in spite of broad countervailing trends, including the fact that people’s likelihood to commit violence decreases as they get older and that gun violence has generally declined in Chicago and across the U.S. since the 1990s. 

Teplin said in an interview that when she first proposed the study, which received funding from the National Institutes of Health, many other researchers dismissed her idea as far too ambitious. 

“People said, ‘You want to do what?’” recalled Teplin. “People said, ‘You won’t be able to sample the kids, the kids won't be cooperative, you won’t be able to track the kids.’” 

Teplin and her co-authors said their study shows that federal intervention is needed to protect at-risk adolescents from gun violence before they become adults. 

One step is to help provide lockboxes for parents who own guns and have children, Teplin said.

“We focus a lot on safe storage and obviously that’s critical and lockboxes aren’t expensive. You can buy a lockbox for $25,” she said. “What is $25 versus a child’s life?”

She said that programs like Operation Childsafe, which works with law enforcement agencies to distribute gun safety kits, should receive federal support. 

However, she added that many adolescents can also obtain firearms outside the home. That risk is especially high in impoverished neighborhoods with large numbers of abandoned buildings. 

“Focus on blighted neighborhoods because they are rife with places to hide guns, trade guns, rent guns,” she said. “We need to invest in these communities.”

Another way to help children affected by guns is to intervene through educational programs at school, similar to sex education classes, according to Teplin. 

“In school we have all kinds of intervention about STIs and everything else, but I’m not aware of programs to reduce violence, to reduce firearm violence,” she said. 

And finally, Teplin said pediatricians should play a role in combating gun violence. Since all children who enroll in school are required to visit the pediatrician to get vaccinations, pediatricians have a unique level of access to both parents and children. 

“The one constant person in children’s lives is their pediatrician,” said Teplin. 

Pediatricians could talk to parents and kids about firearm safety and give coupons to parents to purchase lockboxes, Teplin suggested. 

The study, titled “Association of Firearm Access, Use, and Victimization During Adolescence With Firearm Perpetration During Adulthood in a 16-Year Longitudinal Study of Youth Involved in the Juvenile Justice System,” was published in February 2021 in JAMA Network Open. The co-authors are Linda Teplin, Nicholas Meyerson, Jessica Jakubowski, David Aaby, Nanzi Zheng, Karen Abram and Leah Welty of Northwestern University. Teplin was lead author.