No. 24-1061

JOSEPH R. CAPEN; NATIONAL ASSOCIATION FOR GUN RIGHTS,

Plaintiffs, Appellants,

v.

ANDREA JOY CAMPBELL, in her official capacity as Attorney General of the Commonwealth of Massachusetts,

Defendant, Appellee.

APPEAL FROM THE UNITED STATES DISTRICT COURT FOR THE DISTRICT OF MASSACHUSETTS

[Hon. F. Dennis Saylor, IV, U.S. District Judge]

Before

Gelpí and Rikelman, Circuit Judges, and Katzmann,* Judge.

Barry K. Arrington, with whom Arrington Law Firm was on brief, for appellants.

Erin E. Murphy, Lawrence G. Keane, Paul D. Clement, Matthew D. Rowen, Mariel A. Brookins, and Clement & Murphy, PLLC, on brief for National Shooting Sports Foundation, Inc., amicus curiae.

Grace Gohlke, Assistant Attorney General, with whom Andrea Joy Campbell, Attorney General, and Julie E. Green,

* Of the United States Court of International Trade, sitting by designation. Assistant Attorney General, were on brief, for appellee.

Matthew J. Platkin, Attorney General of New Jersey, Jeremy M. Feigenbaum, Solicitor General, Angela Cai, Deputy Solicitor General, Christopher J. Ioannou, Deputy Attorney General, Rob Bonta, Attorney General of California, Philip J. Weiser, Attorney General of Colorado, William Tong, Attorney General of Connecticut, Kathleen Jennings, Attorney General of Delaware, Brian L. Schwalb, Attorney General for the District of Columbia, Anne E. Lopez, Attorney General of Hawai'i, Kwame Raoul, Attorney General of Illinois, Aaron M. Frey, Attorney General of Maine, Anthony G. Brown, Attorney General of Maryland, Dana Nessel, Attorney General of Michigan, Keith Ellison, Attorney General of Minnesota, Aaron D. Ford, Attorney General of Nevada, Letitia James, Attorney General of New York, Ellen F. Rosenblum, Attorney General of Oregon, Michelle A. Henry, Attorney General of Pennsylvania, Peter F. Neronha, Attorney General of Rhode Island, Charity R. Clark, Attorney General of Vermont, and Robert W. Ferguson, Attorney General of Washington, on brief for New Jersey, California, Colorado, Connecticut, Delaware, the District of Columbia, Hawai'i, Illinois, Maine, Maryland, Michigan, Minnesota, Nevada, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington, amici curiae.

Jennifer Loeb, Aaron R. Marcu, Brandt Henslee, Daniel Hodgkinson, Taylor Jachman, Freshfields Bruckhaus Deringer US LLP, Esther Sanchez-Gomez, Leigh Rome, William T. Clark, Giffords Law Center to Prevent Gun Violence, Douglas N. Letter, Shira Lauren Feldman, Brady Center to Prevent Gun Violence, Ciara Wren Malone, and March for Our Lives on brief for Giffords Law Center to Prevent Gun Violence, Brady Center to Prevent Gun Violence, and March for Our Lives, amici curiae.

April 17, 2025 KATZMANN, Judge. This appeal involves a constitutional challenge to a Massachusetts law that prohibits the sale, transfer, or possession of "an assault weapon or a large capacity feeding device." Mass. Gen. Laws ch. 140, § 131M (the "Massachusetts Ban," or the "Ban").

Appellant Joseph R. Capen is a Massachusetts resident who alleges that he would purchase items covered by the Ban "to keep in his home for self-defense and other lawful purposes" if not for the credible threat of prosecution under § 131M. Appellant the National Association for Gun Rights (the "Association") is a nonprofit organization whose members would also allegedly purchase items prohibited by the Massachusetts Ban for the same purposes if not for that threat.

Appellants filed a complaint in the U.S. District Court for the District of Massachusetts on September 7, 2022, seeking a declaratory judgment that the Ban (1) on its face violates the Second Amendment of the U.S