Age restrictions for handguns make little difference in homicides, study finds

"The central issue is that there's a very high degree of informal access to firearms, such as through family members or illicit channels," said Caitlin Moe, the study's lead author and a PhD student in epidemiology in the UW School of Public Health. "And we can't address that kind of availability with age limits."

The UW study compared homicide rates involving firearms in this age group between five states that increased the minimum age to buy or possess a firearm higher than the nationwide limits set by the 1994 federal law and the 32 states that did not.

The five states were Massachusetts, Maryland, New Jersey, New York and Wyoming. With the exception of Wyoming, these states also increased the minimum age for possession of a handgun. (States that raised age limits before 1994 were not included. Washington was not included for this reason, and the initiative passed in 2018 increasing age limits became law after the study period, which was 1995 to 2017.)

In the study, published in JAMA Pediatrics, UW researchers found that rates of firearm homicides perpetrated by young adults aged 18 to 20 years old were not significantly different in the two groups of states.

Determining what laws do have an effect on homicide rates is paramount, she added, because of the roughly 275,000 homicides involving a firearm during the years studied nearly 36,000 were perpetrated by people in the study's age range. Because most handguns used in crimes by young adults are acquired from sources unlikely to be affected by age restrictions, "it is not surprising that we found no association" between state laws and homicides, the study said.

Also, Moe emphasized, firearms are the second leading cause of death of American youth, after motor vehicle crashes.

"It's incredibly important that we address this major cause of death in young people," said Moe, who is also affiliated with the Harborview Injury Prevention & Research Center. And that solution will need to be a country-wide, unified effort to address the "de facto availability" of firearms, especially among youth.

Co-authors include Miriam Haviland and Andrew Bowen, Harborview Injury Prevention & Research Center; Ali Rowhani-Rahbar and Frederick Rivara, UW Department of Epidemiology, Harborview Injury Prevention & Research Center and the UW Department of Pediatrics. This research was funded by the state of Washington.