For much of the past three decades, a federal funding restriction effectively suppressed public health research into firearm injury and death in the United States, leaving policymakers to debate gun policy with a research base far thinner than exists for most other major causes of preventable death. That funding restriction was significantly loosened in recent years, and the resulting expansion of firearm research has begun to produce a clearer, though still developing, picture of which policy interventions show measurable evidence of reducing gun violence and which remain more uncertain.
Red Flag Laws and Suicide Prevention
Extreme risk protection order laws, commonly known as red flag laws, have accumulated some of the more encouraging evidence among recent firearm policy interventions. These laws allow family members, and in many states law enforcement, to petition a court to temporarily remove firearm access from an individual demonstrating clear warning signs of danger to themselves or others. Research examining states that adopted these laws has found associations with reduced firearm suicide rates, an important finding given that firearm suicides consistently account for a majority of total gun deaths in the United States, a fact that often surprises people whose attention is drawn primarily to mass shooting events covered extensively in the media. Studies specifically modeling the number of suicides averted per protective order issued suggest the laws are a relatively efficient intervention, though researchers note that utilization varies enormously by jurisdiction, with some counties issuing orders at rates many times higher than others, suggesting implementation and awareness gaps significantly affect real-world impact.
Background Checks Show Mixed Results
Background check policy represents one of the more extensively studied areas of firearm regulation, though the research findings are more mixed than for red flag laws. Universal background check requirements, which extend background check obligations to private sales and transfers that federal law otherwise exempts, have been associated with reduced firearm trafficking and reduced rates of firearms being diverted to prohibited possessors in several state-level studies. However, research on the effect of background check laws on overall homicide and suicide rates has produced more inconsistent results across different studies and methodologies, partly because background checks alone do not address the substantial share of firearms already in circulation among people who might misuse them, and partly because enforcement and compliance vary considerably.
Safe Storage and Waiting Periods
Safe storage laws, which require or incentivize firearm owners to store weapons unloaded and locked, separate from ammunition, have a fairly consistent evidence base linking them to reductions in pediatric firearm injuries and deaths, including both unintentional shootings and youth suicides involving household firearms. Research on adolescent suicide specifically has found that access to an unsecured firearm in the home substantially increases suicide risk during moments of acute crisis, a finding that has driven public health messaging campaigns, sometimes conducted in partnership with firearm retailers and shooting ranges, aimed at promoting voluntary safe storage practices even in the absence of legal mandates.
Waiting periods between firearm purchase and delivery, another commonly studied policy, show research support specifically tied to their effect on impulsive violence, particularly suicide, since the period during which someone is at acute risk of suicidal crisis is often short, and a mandatory delay can allow that acute period to pass before a firearm becomes available. Studies examining states that repealed waiting period laws have found subsequent increases in gun deaths, providing a useful natural experiment that strengthens confidence in the causal relationship, since it demonstrates the effect operating in both directions as policy changed.
Permit Requirements and Contested Bans
Minimum age requirements and permit-to-purchase laws, which require prospective buyers to obtain a license involving a more thorough vetting process before purchasing a firearm, have also shown associations with reduced firearm homicide rates in several rigorous state-comparison studies, particularly research examining Connecticut's permit-to-purchase law adoption and Missouri's repeal of a similar law, which researchers have used as a comparative natural experiment given the opposite direction of policy change in the two states around a similar period.
Assault weapons bans and high-capacity magazine restrictions, among the most politically contentious firearm policies, have a comparatively thinner and more contested research base regarding their effect on overall gun death rates, though several studies have found associations between these restrictions and reduced fatalities and injuries specifically in mass shooting incidents, which, while representing a small share of total gun deaths, carry outsized public and psychological impact.
What the expanding body of firearm research suggests overall is that gun violence is not a single problem with a single solution, but several overlapping problems, suicide, domestic violence, community and interpersonal violence, and mass shooting events, that may respond to different policy levers with varying degrees of effectiveness. Researchers studying this area consistently caution against treating any single intervention as sufficient on its own, while also noting that the strengthening evidence base for interventions like red flag laws, safe storage promotion, and waiting periods offers policymakers a firmer empirical foundation than existed even a decade ago, a meaningful shift after years of research being constrained by funding restrictions that limited what could be studied at all.
