Gun deaths among children surge after states loosen firearm laws, new study finds

A new study published Monday in JAMA Pediatrics found that over 7,000 more children died from firearm-related injuries in the years following a 2010 Supreme Court decision that gave states greater power to set their own gun laws. Most of those deaths occurred in states that opted to make it easier to purchase and carry firearms.

The study, led by Dr. Jeremy Faust, an emergency medicine doctor with Mass General Brigham, found a sharp increase in gun-related deaths among children and teens ages 0 to 17 beginning in 2011, following the 2010 McDonald v. Chicago decision, which ruled that the Second Amendment's right to bear arms was applicable to all states and municipalities and ultimately overturned municipal handgun bans like the one previously enforced in Chicago.

Over the 12-year post-decision period, researchers estimate more than 6,000 excess deaths occurred in states with the most permissive gun laws. Another 1,400 excess deaths occurred in states that made their laws more permissive but were not in the most extreme group.

Meanwhile, four states -- California, New York, Maryland, and Rhode Island, all of which had strict laws -- saw significant drops in pediatric gun deaths.

"States that made it easier to obtain and carry a firearm had a tradeoff for that, which was a higher rate of mortality in kids," Faust said.

Researchers analyzed more than two decades of data, comparing trends in gun-related deaths before and after the legal shift. They adjusted for background trends and compared gun deaths to other causes like motor vehicle accidents, overdoses, and cancer.

The increase in deaths was not part of a broader rise in youth mortality -- it was specific to firearms.

This wasn't just about overall violence going up, Faust told ABC News. The change in gun deaths was far greater than any other trend the study looked at, including deaths involving motor vehicle accidents, overdose and even cancer, he said.

Firearms are now the leading cause of death in children and teens in the United States, a distinction not seen in other developed countries. During the 25-year study period, guns were involved in 4% of all pediatric deaths, outpacing motor vehicle crashes and cancer.

The study also found that the increases in firearm deaths were not confined to a single demographic or region. Rates rose in both urban and rural areas, and among all racial and ethnic groups studied. However, non-Hispanic Black children and teens were disproportionately affected in states that had loosened gun laws.

Most of the pediatric gun deaths were not accidental. They were homicides and suicides, deaths that might have been prevented with safer policies or better storage laws, according to the study. In fact, researchers noted that unintentional shootings made up a small share of overall deaths.

Faust acknowledged that there is no one-size-fits-all solution, and that each state may need tailored approaches to address gun violence. He called for continued research and collaboration with policymakers to determine which gun safety laws save the most lives and emphasized the importance of evidence-based policymaking, comparing gun laws to the nationwide mandates for child car seats.

"You can't leave the hospital with a newborn unless you have the right car seat in all 50 states," he noted. "That's because vehicle collisions up until a few years ago were the leading cause of mortality outside of infancy."

Dr. Ilan Kokotek is a board-certified family physician completing training in preventive medicine at the Johns Hopkins Bloomberg School of Public Health and is a member of the ABC News Medical Unit.