STATE FIREARM LAW DATABASE

Our mission is to provide accurate, research-driven data on U.S. state firearm laws, empowering researchers, policymakers, and advocates to develop evidence-based policies that reduce firearm violence.

We envision a future where data-driven research on firearm legislation leads to smarter policies, reduced gun violence, and greater public safety across the U.S.

Our longitudinal gun law database catalogs the presence or absence of 72 firearm safety laws in each of the 50 states from 1976 to 2024. It serves as the most extensive longitudinal panel of state firearm laws assembled to date. To identify provisions for inclusion in the database, we drew heavily from past research on state firearm laws and current state gun policy resources.

In updating the database, we researched the passage of state firearm laws from 2016 to 2024 using Westlaw Edge, a legal research product produced by Thomson Reuters. Laws were identified and coded by four independent research team members. The results compared and any discrepancies resolved by jointly reviewing the specific statutes in question. We relied primarily on historical state Session Laws and historical state annotated statutes. We compared our results with the Giffords website, which provides a comprehensive overview of current firearm laws in all 50 states.

This database should not be interpreted as expressing political views about state firearms legislation. Our sole aim is to provide a comprehensive picture of the historical and current landscape of state firearm laws, so that public health researchers can identify ways to minimize firearm violence. Nothing in this report should be construed as indicating support or opposition to any specific law or policy.

The 72 provisions included in our database are segregated into 11 categories. While we did not include every state gun law ever enacted, we attempted to incorporate the key firearm safety provisions that play a significant role in today’s policy debate. We hope that this resource provides leaders in the field of gun violence prevention with data that will prove helpful in developing evidence-based policy.

Note: In the aftermath of the Supreme Court’s decision in Bruen, many state firearm laws are being challenged in court. In general, we have not revised the law coding when laws have been challenged, even if a temporary injunction was issued putting the enforcement of the law on hold. There is one major exception. In 2022, Oregon voters approved Measure 114, which required permits for the purchase of all firearms and instituted a ban on large capacity ammunition magazines. A temporary injunction was issued to halt the enforcement of this law and that injunction was upheld by the state Court of Appeals. For this reason, we decided not to include these law provisions as having been implemented. Should the state prevail, we will update the database accordingly.

What makes our database somewhat unique is that before coding the laws, we developed a detailed codebook that clearly defines each law, what it must cover, what exemptions are allowed, and other details regarding the scope of the law. For example, some states prohibit firearm possession in schools, but have an exemption that allows teachers to carry guns. We did not code states that had this exemption as having a ban on firearm possession in elementary schools. However, if a state had an exemption that allows trained law enforcement or security personnel to carry firearms in schools, we did count this as a prohibition on firearm possession. Our codebook, which is available on our website, provides a similar level of detail for all 72 firearm law provisions.

It is important to note that there are two ways in which states can go beyond existing federal statutes. First, states can enact legislation that mirrors federal restrictions. While this may seem redundant, it can make a major difference by allowing states to more easily enforce these laws and prosecute violators. Second, states can enact legislation that goes beyond federal statutes. We tracked state laws in both of these categories.
The primary goal of this database is to aid researchers as they evaluate the effectiveness of various firearm laws. To do this, laws must be classified in such a way that they can be compared across state lines. However, state statutes are not uniformly written. Nuanced in language, implementation, and enforcement, each firearm law provision is unique to its state. We aimed to create a classification system that allowed us to categorize provisions using a methodology that both captured their important differences and maintained a level of comparability between states. Because of this, our database is not the most detailed nor the most comprehensive record of all state firearm policies. Other resources may provide users with a deeper understanding of individual provisions, while our database serves as an efficient way to compare the broad scope of state firearm laws across the country.

Outlined below are the 11 categories used to classify the 72 firearm law provisions in our database. The subsequent pages provide detailed explanations of the historical context and legal scope of the provisions that fall within each of these categories.

Dealer Regulations: Establish rules for anyone in the business of selling, lending, or trading firearms.

Buyer Regulations: Laws that gun purchasers must obey in order to obtain a firearm.

Prohibitions for High-Risk Gun Possession: Prevent individuals with a history of crime, especially violent crime, from possessing firearms.

Background Checks: Establish requirements and procedures for firearm sellers to perform background checks on prospective firearm purchasers.

Ammunition Regulations: Establish rules for anyone in the business of buying or selling firearm ammunition.

Possession Regulations: Establish age limitations for firearm possession, conditions under which possession is allowed, and places where gun carrying is permitted.

Concealed Carry Permitting: Outline the process that individuals must undergo to obtain a concealed carry permit in their state.

Assault Weapons and Large-Capacity Ammunition Magazines: Outline state bans on the purchase and/or possession of assault weapons and large capacity ammunition magazines.

Child Access Prevention: Establish rules for the safe storage of firearms in the home.

Domestic Violence: Establish conditions under which individuals convicted of domestic violence-related offenses are prohibited from possessing firearms.

Stand Your Ground Laws: Laws that eliminate the duty to retreat as a first resort when threatened with severe bodily harm and allow a gun owner to shoot first.

Project Director
Michael Siegel, MD, MPH, Professor, Department of Public Health and Community Medicine, Tufts University School of Medicine

Authors
Caitlyn Martinez
Sabrina Robichaud
Ambreen Zaidi
Brooke Wong, MSPH
Jane McClenathan, MPH
Molly Pahn, MPH
Michael Siegel, MD, MPH

Researchers
Caitlyn Martinez, Sabrina Robichaud, Ambreen Zaidi, Brooke Wong, Tiffany Christensen, Alanna Raskin, Abena Dakwahene, Saumya Sankhavaram, Christine Snow, Steve Jang, Chelsea Baker, Megan Greenwood, Yesha Maniar, Clare Schmidt, Meagan Wostbrock, Brittany Ranchoff, Tithi Baul, Woo Choi, Ashlee Epsensen, Alicia Afrah-Boateng, Jessica Christian, Mun Aung, Samuel Siegel, and Miriam Siegel

Database Update Project Co-Investigators
Caitlyn Martinez
Sabrina Robichaud
Ambreen Zaidi
Brooke Wong, MSPH

This web site would not be possible without the significant contributions of Ted Alcorn, Courtney Zale, Liz Avore, Jonas Oransky, Sarah Tofte, Cecily Wallman-Stokes, and Billy Rosen at Everytown for Gun Safety, to whom we are deeply indebted for providing consultation and legislative data.

The previous work of the following individuals made our research possible: Jon S. Vernick, Lisa M. Hepburn, Daniel W. Webster, Peter Cummings, April M. Zeoli, Matthew R. Rosengart, James A. Mercy, Elizabeth R. Vigdor, Scott Burris, and Heidi Grunwald.

We obtained information from the following organizations when conducting our investigation:

– Everytown for Gun Safety
– Law Center to Prevent Gun Violence
– Brady Campaign to Prevent Gun Violence
– Bureau of Alcohol, Tobacco, Firearms, and Explosives
– Bureau of Justice Statistics
– National Rifle Association Institute for Legislative Action
– Legal Community Against Gun Violence
– Legal Science, LLC
– Law Atlas Project

Initial funding for this project (which supported the development of a database covering the period 1981-2016) was provided by the Robert Wood Johnson Foundation, grant #73337, Evidence for Action: Investigator-Initiated Research to Build a Culture of Health. The views expressed here do not necessarily reflect the views of the Foundation.

Funding for extending the database back to 1976 was provided by the National Institute of Justice, grant #2018-75-CX-0025, awarded by the Office of Justice Programs, US Department of Justice. The opinions, findings, and conclusions or recommendations expressed in this publication are those of the authors and do not necessarily reflect those of the Department of Justice.

Funding for the updating of the database forwards to 2024 was provided by the Tufts Clinical and Translational Science Institute (CTSI). Special thanks to Alice M. Rushforth, PhD, Associate Dean, Programs and Partnerships, Tufts CTSI; Assistant Professor of Medicine, Tufts University School of Medicine.

The views expressed here do not necessarily reflect those of Tufts University, Tufts CTSI, or the Tufts University School of Medicine.