Application of 18 U.S.C. § 930(a) to Post Offices

(Slip Opinion) Application of 18 U.S.C. § 930(a) to Post Offices Section 930(d)(3) of title 18, U.S. Code, permits the lawful carrying of constitutionally protected firearms in post offices that are generally open to the public. August 12, 2026 MEMORANDUM OPINION FOR THE ATTORNEY GENERAL Congress has passed at least nine different statutes that bar or have been interpreted to bar otherwise law-abiding citizens from carrying weapons into designated locations. 1 It has also empowered the Depart- ment of Homeland Security, 40 U.S.C. § 1315(c), as well as individual federal agencies, see, e.g., 39 U.S.C. §§ 401(2), 403(b)(3) (Postal Ser- vice),2 to regulate who may enter the buildings that they own and operate. Many of those agencies have opted to bar weapons from their facilities and grounds either explicitly by regulation 3 or implicitly by closing their facilities to the public.4 1 See 15 U.S.C. § 1243 (switchblade knives in federal enclaves); id. § 1245(a) (ballistic knives in federal enclaves); 18 U.S.C. § 922(q)(2) (school zones); id. § 930(a) (federal facilities); id. § 930(e) (federal court facilities); id. § 1791(a)(1), (d)(1)(A) (prisons); id. § 2277 (seized vessels); 40 U.S.C. § 5104(e)(1)(A) (U.S. Capitol Buildings and Grounds); 49 U.S.C. § 46505 (commercial aircraft). 2 See also 10 U.S.C. § 2672 note (military installations); 18 U.S.C. § 1752(a)(1), (b)(1) (buildings that house individuals protected by the Secret Service or designated events); 40 U.S.C. § 6102 (Supreme Court regulations); 42 U.S.C. § 2278a (Nuclear Regulatory Commission installations); 50 U.S.C. § 797 (defense property security regulations); 54 U.S.C. § 104906 (national parks). 3 See 4 C.F.R. § 25.14 (Government Accountability Office); 7 C.F.R. § 500.12(a) (U.S. National Arboretum property); id. § 501.12 (U.S. Meat Animal Research Center); id. § 502.13 (Beltsville Agriculture Research Center); id. § 503.13 (Plum Island Animal Disease Center); 10 C.F.R. § 73.81(c) (nuclear facilities); 14 C.F.R. ֻ§ 135.119 (aircraft); id. § 1204.1003(a)(2) (National Aeronautics and Space Administration); 15 C.F.R. § 265.39 (National Institutes of Standards and Technology); 28 C.F.R. § 541.3 (Bureau of Prisons facilities); 31 C.F.R. § 91.13 (Bureau of the Mint buildings and grounds); id. § 407.13 (Treasury building and annex); id. § 700.11 (Federal Law Enforcement Training Center); 32 C.F.R. § 228.7 (National Security Agency); id. § 234.10 (Pentagon); id. § 552.120 (Fort Lewis); id. § 1903.10 (Central Intelligence Agency); 33 C.F.R. § 207.20(q)(10) (Cape Cod Canal); 36 C.F.R. § 13.1210 (Katmai National Park); id. § 327.13 (water resource development projects); id. § 331.3(b) (Ohio National Wildlife Conservation Area); id. § 504.14 (Smithsonian Institution premises); id. § 520.15 (Na- 1  50 Op. O.L.C. __ (Aug. 12, 2026) You have asked whether one of those restrictions, codified at 18 U.S.C. § 930(a), is best read to impose criminal penalties on an otherwise law- abiding individual who carries weapons into a post office for the purpose of self-defense. We would have significant constitutional concerns if Congress had created such a blanket ban on the lawful carrying of consti- tutionally protected arms into a building frequented by the public since the Founding. But we ultimately need not reach that issue here, as Con- gressֻhasֻexemptedֻtheֻ“lawfulֻcarrying”ֻofֻfirearmsֻorֻotherֻdangerousֻ weaponsֻ “incidentֻ toֻ huntingֻ orֻ otherֻ lawfulֻ purposes.” 18 U.S.C. § 930(d)(3). Because carrying arms for self-defense when entering a buildingֻheldֻopenֻtoֻtheֻpublicֻisֻaֻparadigmaticֻ“lawfulֻpurpose[],”ֻthatֻ exception permits the lawful carrying of constitutionally protected fire- arms in post offices. Id. I. As part its prosecution of the global War on Drugs, Congress made possession of firearms and other dangerous weapons in federal facilities a felony in 1988. See Anti-Drug Abuse Amendments Act of 1988, Pub. L. No. 100-690, tit. VI, § 6215(a), 102 Stat. 4312, 4361–62. Congress pro- videdֻthat,ֻsubjectֻtoֻthreeֻexceptions,ֻ“whoeverֻknowinglyֻpossessesֻorֻ causes to be present a firearm or other dangerous weapon in a Federal facility (other than a Federal courtֻfacility),ֻorֻattemptsֻtoֻdoֻso,”ֻwouldֻ beֻ subjectֻ toֻ fines,ֻ imprisonmentֻ ofֻ “notֻ moreֻ thanֻ 1 year,ֻ orֻ both.” 18 U.S.C. § 930(a). Congressֻdefinedֻ“dangerousֻweapon”ֻtoֻincludeֻanyֻ “weapon,ֻdevice,ֻinstrument,ֻmaterial,ֻorֻsubstance,ֻanimateֻorֻinani- mate, that is used for, or is readily capable of, causing death or serious bodily injury, except that such term does not include a pocket knife with a tional Zoological Park); id. § 702.7 (Library of Congress); id. § 1002.4 (Presidio Trust); id. § 1280.14(a) (National Archives and Records Administration); 39 C.F.R. § 232.1(l) (U.S. Postal Service property); 44 C.F.R. § 15.15 (certain Federal Emergency Manage- ment Agency facilities); 45 C.F.R. § 3.42(g) (National Institutes of Health Federal Enclave); 46 C.F.R. § 386.23 (U.S. Merchant Marine Academy); 49 C.F.R. § 1540.111 (aircraft and secure areas in airports); 50 C.F.R. § 27.41 (National Wildlife Refuge System); Sup. Ct. Bldg. Regul. 3. 4 See, e.g.,ֻU.S.ֻEnv’tֻProt.ֻAgency,ֻ Visiting EPA: Building Access (July 8, 2026), https://perma.cc/FM5T-DSML; Internal Revenue Serv., Contact Your Local IRS Office (July 14, 2026), https://perma.cc/8P94-HKAL; Fed. Bureau of Investigation, Contact Us: FBI Headquarters, https://perma.cc/G6RQ-DLFA (last accessed Aug. 3, 2026). 2  Application of 18 U.S.C. § 930(a) to Post Offices bladeֻofֻlessֻthanֻ[2.5]ֻinchesֻinֻlength,”ֻid. § 930(g)(2),ֻandֻaֻ“Federalֻ facility”ֻtoֻincludeֻanyֻ“buildingֻorֻpartֻthereofֻownedֻorֻleasedֻbyֻtheֻ Federal Government, where Federal employees are regularly present for theֻpurposeֻofֻperformingֻtheirֻofficialֻduties,”ֻid. § 930(g)(1). A post office is unquestionably a facility within the meaning of section 930. See, e.g., Nastri v. Bondi, 828 F. Supp. 3d 316, 330–31 (D. Conn. 2026). The Postal Service is part of the Executive Branch, and its employ- ees are federal employees. See 39 U.S.C. §§ 201, 1001. As of fiscal year 2025, the Postal Service owned or leased almost 31,000 retail offices across the United States. See U.S. Postal Serv., Postal Facts: Size and Scope (2024), https://perma.cc/K7Q5-F9YB. These federally owned or leased offices, where Postal Service employees perform their duties, are federal facilities under the definition of that term in section 930. See 18 U.S.C. § 930(g)(1). Section 930(d) lists three exceptions to the general prohibition against possessing firearms in federal facilities. The prohibition does not apply to: (1) the lawful performance of official duties by an officer, agent, or employee of the United States, a state, or a political subdivision thereof, who is authorized by law to engage in or supervise the prevention, detection, investigation, or prosecution of any viola- tion of law; (2) the possession of a firearm or other dangerous weapon by a feder- al official or a member of the Armed Forces if such possession is authorized by law; or (3) the lawful carrying of firearms or other dangerous weapons in a federal facility incident to hunting or other lawful purposes. Id. § 930(d)(1)–(3). Because your question concerns members of the general public, the third exception, which allows the carrying of a firearm or other dangerous weaponֻ“incidentֻtoֻhuntingֻorֻotherֻlawfulֻpurposes,”ֻisֻmostֻrelevantֻ here. Id. § 930(d)(3). Thereֻhasֻbeenֻ“veryֻlittleֻcaseֻlawֻexploringֻtheֻ scopeֻofֻ[the]ֻ‘otherֻlawfulֻpurposes’”ֻexception. Yorzinski v. Imbert, 39 F. Supp. 3d 218, 227 (D. Conn. 2014). When the exception has arisen in litigation,ֻtheֻDepartmentֻofֻJusticeֻhasֻarguedֻthatֻ“theֻscopeֻofֻ‘otherֻ lawfulֻpurpose’ֻisֻinformedֻbyֻtheֻspecificֻexampleֻthatֻtheֻstatuteֻpro- vides:ֻhunting.” Government’sֻSupplementalֻBriefֻtoֻDefendant’sֻMotionֻ 3  50 Op. O.L.C. __ (Aug. 12, 2026) to Dismiss Indictment at 19, United States v. Ayala, 711 F. Supp. 3d 1333 (M.D. Fla. 2024), Dkt. 32. And two district courts appear to have agreed that,ֻatֻminimum,ֻtheֻfirearmֻmustֻbeֻlawfullyֻcarriedֻforֻaֻ“purposeֻthatֻ isֻrelatedֻtoֻtheֻfederalֻfacility”ֻintoֻwhichֻitֻwasֻcarried. United States v. De la Cruz-Bancroft, No. 09-cr-319, 2010 WL 8752034, at *2 (D.N.M. Jan. 4, 2010); cf. Yorzinski, 39 F. Supp. 3d at 227 (citing favorably De la Cruz-Bancroft, 2010 WL 8752034, at *2–3). II. You have asked whether the Department should continue to take a nar- rowֻviewֻofֻtheֻ“lawfulֻpurposes”ֻexception,ֻallowingֻtheֻimpositionֻofֻ criminal penalties on otherwise law-abiding individuals who carry weap- ons into a post office for the purpose of self-defense. It should not. A. Toֻreiterate,ֻsectionֻ930(d)(3)ֻprovidesֻthatֻsectionֻ930(a)’sֻbarֻagainstֻ carryingֻfirearmsֻandֻdangerousֻweaponryֻdoesֻnotֻapplyֻtoֻ“theֻlawfulֻ carrying of firearms or other dangerous weapons in a Federal facility incidentֻtoֻhuntingֻorֻotherֻlawfulֻpurposes.” 18 U.S.C. § 930(d)(3). To fall within this exception with respect to firearms, an individual must satisfy two criteria: (1) theֻcarryingֻofֻtheirֻfirearmֻmustֻbeֻ“lawful”;ֻandֻ (2) theֻcarryingֻmustֻbeֻ“incidentֻto”ֻaֻ“lawfulֻpurpose[],”ֻsuchֻasֻ“hunt- ing.” Id. 1. The first requirement is relatively straightforward. It excludes, for ex- ample, a person who is not legally allowed to carry a gun anywhere. This requirement considers both state and federal law. Cf. United States v. Johnson,ֻ968ֻF.2dֻ208,ֻ212ֻ(2dֻCir.ֻ1992)ֻ(interpretingֻtheֻtermֻ“lawful”ֻ in 18 U.S.C. § 1512(d)ֻbyֻitsֻ“ordinaryֻmeaning”ֻandֻthenֻconsideringֻ theֻinterplayֻbetweenֻstateֻlawֻandֻfederalֻlawֻofֻstandardsֻforֻ“lawfulֻ conduct”ֻ(citationֻomitted)). Under federal law, this exemption would not cover, for example, a person who has been convicted of a felony or a misdemeanor crime of domestic violence, a person who has been commit- ted to a mental institution, or a person who is in the United States illegal- ly. See 18 U.S.C. § 922(g)(1), (4), (5)(A), (9). It may also exclude an 4  Application of 18 U.S.C. § 930(a) to Post Offices individual who is forbidden from carrying a firearm in the relevant state because he is not licensed—so long as the licensing regime itself is not constitutionally infirm. Cf. United States v. Tait, 202 F.3d 1320, 1323–25 (11th Cir. 2000) (finding that the defendant, who was licensed to carry a firearm under Alabama law, did not violate a federal law prohibiting possession of firearms in a school zone). 2. The second requirement is less clear but is best read to cover an indi- vidual entering a post office that is open to the public while lawfully carrying a firearm for self-defense. “Incident,”ֻ usedֻ asֻ anֻ adjective,ֻ meansֻ“occurringֻorֻlikelyֻtoֻoccurֻesp[ecially] as a minor consequence orֻ accompaniment.” Webster’s Ninth New Collegiate Dictionary 609 (1985).5 Inֻtheֻlegalֻcontext,ֻ“incident”ֻmeansֻ“dependsֻupon,ֻappertainsֻ to,ֻorֻfollowsֻanother.” Black’s Law Dictionary 686 (5th ed. 1979).6 But sectionֻ930(d)(3)ֻdoesֻnotֻspecifyֻwhetherֻtheֻ“lawfulֻpurpose”ֻtoֻwhichֻ the carrying of a firearm must accompany is the purpose for entering a federal building or the purpose for carrying the firearm. Read in conjunc- tion with background principles of law, we think the better view is that an individual needs both a lawful purpose to be in a federal facility and a lawful purpose to carry a firearm in order for the individual to qualify for the exception in section 930(d)(3), but not necessarily that the two must be related. So understood, an otherwise law-abiding citizen who carries a constitutionally protected firearm into a post office that is generally open to the public would fall within the scope of that exception. Underֻ theֻ “grammaticalֻ ‘ruleֻ ofֻ theֻ lastֻ antecedent,’ֻ . . . a limiting clauseֻorֻphrase”—here,ֻ“incidentֻtoֻhuntingֻorֻotherֻlawfulֻpurpose”— “shouldֻordinarilyֻbeֻreadֻasֻmodifyingֻonlyֻtheֻnounֻorֻphraseֻthatֻitֻ 5 See also Webster’s Third New International Dictionary 1142 (1986 ed.) (same); Web- ster’s II New Riverside University Dictionary 618ֻ(1988ֻed.)ֻ(“[t]endingֻtoֻariseֻorֻoccurֻ asֻaֻconcomitant”);ֻThe American Heritage Dictionary 650 (2d coll. ed. 1982) (same); The Random House Dictionary of the English Language 966ֻ(2dֻed.ֻ1987)ֻ(“likelyֻorֻaptֻ toֻhappen”). 6 See also Webster’s Ninth New Collegiate Dictionary atֻ 609ֻ (“dependentֻ onֻ orֻ relatingֻ toֻ anotherֻ thing”);ֻ Webster’s II New Riverside University Dictionary at 618 (“[c]ontingentֻuponֻorֻrelatedֻtoֻsomethingֻelse”);ֻThe American Heritage Dictionary at 650 (same); Webster’s Third New International Dictionary atֻ1142ֻ(“dependentֻonֻorֻ appertainingֻtoֻanotherֻthing”). 5  50 Op. O.L.C. __ (Aug. 12, 2026) immediatelyֻfollows.” Barnhart v. Thomas, 540 U.S. 20, 26 (2003); see also, e.g., Antonin Scalia & Bryan A. Garner, Reading Law: The Interpre- tation of Legal Texts 144–46ֻ(2012)ֻ(“Scaliaֻ&ֻGarner”). Whileֻ“quiteֻ sensibleֻasֻaֻmatterֻofֻgrammar,”ֻhowever,ֻtheֻlast-antecedentֻ“ruleֻisֻnotֻ anֻabsolute,”ֻandֻinֻthisֻinstanceֻmustֻ“assuredlyֻbeֻovercomeֻbyֻotherֻ indiciaֻofֻmeaning.” Barnhart, 540 U.S. at 26 (quoting Nobelman v. Am. Sav. Bank, 508 U.S. 324, 330 (1993)). In this instance, the rule of the last antecedent would suggest that sec- tionֻ930’sֻlawful-purposeֻrequirementֻmodifiesֻ“Federalֻfacility”—that is, it would imply that an individual would need to enter the facility lawfully because it is open to the public or that the individual is an in- vitee. Such an understanding accords with the background principle that “[w]hereֻaֻcommon-law principle is well established, [we] may take it as given that Congress has legislated with an expectation that the principle willֻapply”ֻabsentֻaֻclearֻindicationֻtoֻtheֻcontrary. Impression Prods., Inc. v. Lexmark Int’l, Inc., 581 U.S. 360, 378 (2017) (cleaned up); see also, e.g., Jones v. Hendrix, 143 S. Ct. 1857, 1876–77 (2023). “Atֻcom- mon law, opening up private property to the general public implies a ‘licenseֻtoֻallֻpersonsֻtoֻenter,’ֻmeaningֻthatֻ‘noֻpersonֻisֻaֻtrespasserֻbyֻ merelyֻenteringֻtherein’ֻunlessֻtheֻpropertyֻownerֻhasֻgivenֻ‘dueֻnotice’ֻ thatֻsuchֻaֻpersonֻisֻbanned.” Wolford v. Lopez, 146 S. Ct. 2032, 2045 (2026) (quoting Commonwealth v. Power, 48 Mass. (7 Met.) 596, 602 (1844)); see also 3 William Blackstone, Commentaries *209. Applied here, as a property owner, the federal government can prohibit weapons on its property, including (within constitutional limits) by closing its property to the public. Wolford, 146 S. Ct. at 2045. But the default rule isֻthatֻ“all [may] enter private property open to the public unless specifi- callyֻ prohibited.” Id. at 2045 (emphasis in original); see also infra Part II.B.3. But,ֻasֻinֻallֻstatutoryֻinterpretation,ֻ“contextֻmatters.” Cutter v. Wil- kinson, 544 U.S. 709, 723 (2005) (cleaned up); see, e.g., Revocation of Prior Monument Designations, 49 Op. O.L.C. __, at *22–23 (May 27, 2025). The context of section 930(d)(3) suggests that following the last- antecedent canon would lead to an incomplete picture. The complete exceptionֻ allowsֻ “theֻ lawfulֻ carryingֻ ofֻ firearmsֻ orֻ otherֻ dangerousֻ weapons in a Federal facility incident to hunting or other lawful purpos- es.” 18 U.S.C. § 930(d)(3). Aֻ“facility”ֻisֻaֻ“buildingֻorֻpartֻthereof.” Id. § 930(g)(1). Because hunting with firearms is an activity that must occur 6  Application of 18 U.S.C. § 930(a) to Post Offices outdoors, see, e.g., Wildlife Pres., Inc. v. Romero, 153 F.4th 192, 204 n.12 (2d Cir. 2025) (citation omitted), 7 weֻ thinkֻ thatֻ “incidentֻ toֻ aֻ lawfulֻ purpose”ֻmustֻbeֻunderstoodֻdistributively. Cf. Scalia & Garner at 214. That is, although the last-antecedent canon is a good rule of thumb (and grammar),ֻ“sometimesֻwhereֻaֻsentenceֻcontainsֻseveralֻantecedentsֻandֻ severalֻconsequents,”ֻtheֻreaderֻshouldֻ“applyֻtheֻwordsֻtoֻtheֻsubjectsֻ which,ֻbyֻcontext,ֻtheyֻseemֻmostֻproperlyֻtoֻrelate.” Encino Motorcars, LLC v. Navarro, 584 U.S. 79, 87 (2018) (cleaned up); see also 2A N. Singer & S. Singer, Sutherland Statutes and Statutory Construction § 47:26, p. 448 (rev. 7th ed. 2014). Here, this principle supports interpret- ing the statute to require that both the entry into the federal facility and the carrying of the firearm must be for a lawful purpose. This understanding tracks everyday experience with post offices. While most post offices are open to the public, that is not universally the case: There are postal facilities on military bases and past the security cordons at airports. Each is subject to its own statutes and regulations, which limit access to something less than the general public. E.g., 10 U.S.C. § 2672 note (military installations); 49 C.F.R. § 1540.111 (airports and aircraft). And there are entirely lawful reasons to bring a firearm into a post office. Forֻexample,ֻweֻrecentlyֻconcludedֻthatֻ“theֻExecutiveֻBranchֻmayֻnot,ֻ consistentֻwithֻtheֻConstitution,ֻenforceֻsectionֻ1715”ֻofֻtitle 18 to the U.S.ֻCodeֻtoֻcriminalizeֻtheֻmailingֻofֻ“constitutionallyֻprotectedֻfire- arms”—a conclusion whose reasoning necessarily implies that section 930(a) cannot be enforced in a way that makes it a felony to carry the boxed firearm into the facility from which it would be mailed. Constitu- tionality of 18 U.S.C. § 1715, 50 Op. O.L.C. __, at *15 (Jan. 15, 2026). Carrying arms for self-defense when entering a building held open to the public is a paradigmatic lawful purpose. 8 The Supreme Court recog- 7 True, it is theoretically possible that one might enter a federal facility while hunting on federal land—for example, to use the restroom or to pick up paperwork while hunting in a national park. But we do not think that is the most natural reading of the statute, as suchֻeventsֻcanֻhardlyֻbeֻdescribedֻasֻ“likelyֻtoֻoccur.” Webster’s Ninth New Collegiate Dictionary at 609 (definingֻ“incident”). 8 For the avoidance of doubt, our conclusion does not extend to firearms and other “dangerousֻweapon[s],”ֻasֻdefinedֻinֻtheֻstatute,ֻ18 U.S.C. § 930(g)(2), that are prohibit- ed by law, such as undetectable firearms, see id. § 922(p)(1). As discussed below, infra Part II.B, our analysis is informed by the Second Amendment—a right that extends only toֻ“theֻpossessionֻandֻuseֻofֻweaponsֻthatֻareֻ‘inֻ commonֻuse.’” N.Y. State Rifle & 7  50 Op. O.L.C. __ (Aug. 12, 2026) nized as much in District of Columbia v. Heller, when it unequivocally statedֻthatֻ“theֻinherentֻrightֻofֻself-defense”ֻisֻ“centralֻtoֻtheֻSecondֻ Amendmentֻright.” 554 U.S. 570, 628 (2008). And it built on the point in its recent Wolford decision, which recognized that people who carry firearms for self-defenseֻregularlyֻvisitֻplacesֻopenֻtoֻtheֻpublicֻ“inֻtheֻ course of their daily routines, such as gas stations, convenience stores, restaurants,ֻcoffeeֻshops,ֻdrugֻstores,ֻgroceryֻstores,ֻ‘bigֻbox’ֻstores,ֻ home improvement stores, barber shops or hair salons, dry cleaners, and laundromats.” 146 S. Ct. at 2040–41. Although run by the federal gov- ernment, a post office open to the public is a retail establishment that is analogous to these locations, requiring (typically) brief visits by law- abiding citizens to acquire everyday goods and services. Unless the prop- erty owner has clearly closed the property to firearms being carried for self-defense, such carrying is presumptively lawful. See id. at 2049 & n.10. Yet far from closing post offices to firearms, Congress expressly permitted the carrying of firearms incident to any lawful purpose. Interpretingֻ“lawfulֻpurpose”ֻinֻsectionֻ930ֻtoֻincludeֻself-defense in a building held open to the public is also consistent with other rules of statutory construction. For example, take the semantic canons of noscitur a sociis and ejusdem generis. See Yates v. United States, 574 U.S. 528, 543, 545–46 (2015) (plurality opinion). In the Second Amendment con- text, hunting is often paired with self-defense as an archetypal lawful purpose. See, e.g., 15 U.S.C. § 7901(b)(2)ֻ(outliningֻCongress’sֻpurposeֻ ofֻ“preserv[ing]ֻaֻcitizen’sֻaccessֻtoֻaֻsupplyֻofֻfirearmsֻandֻammunitionֻ for all lawful purposes, including hunting, self-defense, collecting, and competitiveֻorֻrecreationalֻshooting”). 9 So if an individual who is not legally disabled from possessing a firearm enters a post office that is held Pistol Ass’n, Inc. v. Bruen, 142 S. Ct. 2111, 2128 (2022) (quoting Heller, 554 U.S. at 627). Theֻcarryingֻofֻprohibitedֻweaponsֻdoesֻnotֻsatisfyֻsectionֻ930(d)(3)’sֻrequirementֻ thatֻtheֻcarryingֻbeֻ“lawful.” 9 See also 18 U.S.C. § 922ֻnoteֻ(outliningֻCongress’sֻpurposeֻasֻbeingֻ“toֻavoidֻhin- dering industry from supplying firearms to law abiding citizens for all lawful purposes, including hunting, self-defense,ֻcollecting,ֻandֻcompetitiveֻorֻrecreationalֻshooting”);ֻ Heller,ֻ554ֻU.S.ֻatֻ599ֻ(“[P]reservingֻtheֻmilitiaֻwasֻ[not]ֻtheֻonlyֻreasonֻAmericansֻ valued the ancient right [of bearing arms]; most undoubtedly thought it even more important for self-defenseֻandֻhunting.”);ֻid. at 636–37 (Stevens, J., dissenting) (noting “nonmilitaryֻ purposesֻ [forֻ bearingֻ arms]ֻ likeֻ huntingֻ andֻ personalֻ self-defense”);ֻ McDonald v. City of Chicago,ֻ561ֻU.S.ֻ742,ֻ891ֻ(2010)ֻ(Stevens,ֻJ.,ֻdissenting)ֻ(“Gunsֻ may be useful for self-defense, as well as for hunting and sport . . . .”). 8  Application of 18 U.S.C. § 930(a) to Post Offices open to the public while properly carrying a firearm for self-defense, sectionֻ930(d)(3)ֻappliesֻtoֻexemptֻthemֻfromֻsectionֻ930(a)’sֻcarryingֻ ban,ֻasֻtheֻindividualֻisֻ“lawful[ly]ֻcarrying”ֻaֻfirearmֻ“incidentֻto”ֻaֻ “lawfulֻpurpose[].” 18 U.S.C. § 930(d)(3). Ourֻunderstandingֻalsoֻhelpsֻtoֻ“interpretֻtheֻstatute,”ֻtogetherֻwithֻ otherֻfederalֻfirearmsֻrestrictions,ֻ“asֻaֻsymmetricalֻandֻcoherentֻregula- toryֻscheme”—includingֻhowֻitֻ“mayֻbeֻaffectedֻbyֻotherֻActs,ֻparticu- larlyֻwhereֻCongressֻhasֻspokenֻsubsequently.” FDA v. Brown & Wil- liamson Tobacco Corp., 529 U.S. 120, 133 (2000) (quoting Gustafson v. Alloyd Co., 513 U.S. 561, 569 (1995)). It is unclear why Congress would need to have more than a dozen different statutes regulating the posses- sion of firearms on certain types of federal property, see, e.g., 40 U.S.C. § 5104(e)(1)(A); 42 U.S.C. § 2278a, if section 930(a) created a near- blanket ban on carrying in all federal facilities. This is particularly so givenֻthatֻitsֻ“wordsֻdescribeֻanֻelementֻofֻaֻcriminalֻoffense.” Ratzlaf v. United States, 510 U.S. 135, 140–41 (1994) (citing Pa. Dep’t of Pub. Welfare v. Davenport, 495 U.S. 552, 562 (1990); Potter v. United States, 155 U.S. 438, 446 (1894)). Toֻtakeֻaֻspecificֻexample,ֻshortlyֻafterֻtheֻCourt’sֻdecisionֻinֻHeller, Congressֻrecognizedֻtheֻrightֻtoֻbearֻarmsֻunderֻtheֻ“2dֻamendmentֻtoֻ theֻConstitution,”ֻ54 U.S.C. § 104906(a)(1), and it prohibited the Secre- taryֻofֻtheֻInteriorֻfromֻ“promulgat[ing]ֻorֻenforc[ing] any regulation thatֻprohibitsֻan”ֻotherwiseֻlaw-abidingֻ“individualֻfromֻpossessingֻaֻ firearm,ֻincludingֻanֻassembledֻorֻfunctionalֻfirearm,”ֻwithinֻtheֻNation- al Park System, id. § 104906(b). The National Park Service has interpret- ed the resulting statutory structure as entitling law-abiding citizens to carry firearms onto parklands (under section 104906) but not into park buildings (under a narrow view of section 930(d)(3)). A person who is carrying a firearm on parklands for self-defense but who has to disarm beforeֻenteringֻaֻbuildingֻwouldֻnotֻonlyֻrenderֻhimselfֻ“vulnerableֻforֻ th[e]ֻperiodֻofֻtime”ֻduringֻwhichֻheֻwasֻdisarmed,ֻWolford, 146 S. Ct. at 2048, he would potentially be arming an aggressor who could collect the firearm.10 We, like the courts, will reject such an interpretation that 10 This does not even account for other risks of leaving a firearm outside of a building in an area frequented by the public—for example, the risk that a child visitor may stumble upon the firearm while their parents are inside and accidentally harm themselves. 9  50 Op. O.L.C. __ (Aug. 12, 2026) “make[s]ֻ aֻ hash”ֻ ofֻ theֻ overallֻ statutoryֻ scheme. Becerra v. Empire Health Found., 142 S. Ct. 2354, 2364 (2022). B. This interpretation is further supported by the canon of constitutional avoidance,ֻwhichֻ“imposes”—at minimum—aֻ“‘clarityֻtax’ֻonֻCongress”ֻ when it legislates in ways that raise constitutional doubts. Application of the Rehabilitation Act and Americans with Disabilities Act to State Insti- tutionalization of Patients with Severe Mental Illness or Disabilities, 50 Op. O.L.C. __, at *12 (June 18,ֻ2026)ֻ(“Integration Mandate”) (quot- ing Biden v. Nebraska, 143 S. Ct. 2355, 2376–77 (2023) (Barrett, J., concurring)); see also John F. Manning, Clear Statement Rules and the Constitution, 110 Colum. L. Rev. 399, 403 (2010)). 11 Here, although we need not definitively resolve the issues implicated by them, we have such doubts regarding whether requiring an otherwise law-abiding citizen to disarmֻbeforeֻenteringֻaֻpostֻofficeֻwouldֻsurviveֻtheֻSupremeֻCourt’sֻ two-stepֻanalysisֻthatֻ“look[s]ֻtoֻhistory”ֻinֻorderֻtoֻdetermineֻwhetherֻaֻ restrictionֻfallsֻwithinֻtheֻtraditionalֻ“scopeֻofֻtheֻright”ֻtoֻbearֻarms. Wolford, 146 S. Ct. at 2042. The very existence of those doubts counsels in favor of a broad interpretation of the exception in section 930(d)(3) as applied to post offices.12 11 As we have previously recognized, this is the weaker of two versions of the constitu- tional-avoidance canon. See Whether Eluding Inspection Under 8 U.S.C. § 1325(a)(2) Is a Continuing Offense, 49 Op. O.L.C. __, at *10–11 (June 21, 2025). In its stronger form, the canon can require that we read implicit exceptions into statutes that are otherwise unqualified in scope. See, e.g., Application of 28 U.S.C. § 458 to Presidential Appoint- ments of Federal Judges, 19 Op. O.L.C. 350, 350–57ֻ(1995)ֻ(“Application of 28 U.S.C. § 458”). Theֻexistenceֻofֻtheֻ“lawfulֻpurpose”ֻexceptionֻinֻsectionֻ930(d)ֻobviatesֻtheֻ need to determine whether to imply such an exception under the strong form of constitu- tional avoidance—a form of reasoning that is, in many ways, indistinguishable from holding that section 930(a) is unconstitutional in certain applications. 12 For the avoidance of doubt, although our constitutional analysis under the first step of New York State Rifle & Pistol Ass’n, Inc. v. Bruen’sֻtwo-prong approach applies to section 930(a) outside the context of post offices, we have not undertaken performing the historical analysis required under Bruen’s second step in any other context. Thus, nothing in Parts II.B.2 or II.B.3 of this opinion should be understood to reach any conclusions about other federal facilities. 10  Application of 18 U.S.C. § 930(a) to Post Offices 1. The right to keep and bear arms pre-dates the Constitution. We “codified”ֻ inֻ theֻ SecondֻAmendmentֻ aֻ “pre-existingֻ right,”ֻ rootedֻ inֻ natureֻandֻ“inheritedֻfromֻourֻEnglishֻancestors.” Bruen, 142 S. Ct. at 2127 (cleaned up); see also, e.g., William Baude & Robert Leider, The General-Law Right to Bear Arms, 99 Notre Dame L. Rev. 1465, 1468–69 (2024). Thereֻ isֻ littleֻ roomֻ forֻ doubtֻ thatֻ sectionֻ 930(a)ֻ “clashesֻ withֻ theֻ ‘plainֻtext’ֻofֻtheֻ[Second]ֻAmendment’sֻlanguage”—regardless of the government building to which it is applied. Wolford, 146 S. Ct. at 2043 (quoting Bruen, 142 S. Ct. at 2129–30). Theֻstatuteֻappliesֻtoֻ“theֻpeo- ple”—thatֻis,ֻ“membersֻofֻtheֻpoliticalֻcommunity.” Id. (quoting Heller, 554 U.S. at 580); see also United States v. Verdugo-Urquidez, 494 U.S. 259, 265 (1990). Itֻ concernsֻ “Arms,”ֻ U.S.ֻ Const.ֻ amend. II—that is, “weapon[s]ֻcustomarilyֻusedֻforֻoffensiveֻorֻdefensiveֻpurposes,”ֻWol- ford, 146 S. Ct. at 2043. Specifically, section 930(a) prohibits individuals fromֻ “bear[ing]”—thatֻ is,ֻ “carrying”—those arms. Id. (alteration in original) (quoting Bruen, 142 S. Ct. at 2134–35). Because it falls within theֻplainֻtextֻofֻtheֻSecondֻAmendment,ֻtheֻrestrictionֻisֻ“presumptivelyֻ unconstitutional.” Id. at 2044. 2. As applied to post offices that are generally open to the public, we have grave doubts that the government could carry its burden to overcome that presumptionֻ byֻ demonstratingֻ theֻ restrictionֻ “isֻ consistentֻ withֻ theֻ Nation’sֻhistoricalֻtraditionֻofֻfirearmֻregulation.” Bruen, 142 S. Ct. at 2130. That would be a high hurdle because, for nearly two centuries, there was no “historicalֻtraditionֻofֻfirearmֻregulation”ֻinֻpostֻoffices. Id.; see also id. at 2135. Moreover, it is unlikely that the government would be ableֻtoֻovercomeֻthatֻhurdleֻbyֻreferenceֻtoֻtheֻ“sensitiveֻplaces”ֻdoc- trine because ordinary post offices appear to bear no legally significant resemblanceֻtoֻtheֻ“legislativeֻassemblies,ֻpollingֻplaces,ֻandֻcourthous- es”ֻwhereֻtheֻCourtֻhasֻacceptedֻthatֻtheֻgovernmentֻmayֻpresumptivelyֻ restrict firearms. Id. at 2133. 11  50 Op. O.L.C. __ (Aug. 12, 2026) a. WhenֻevaluatingֻwhetherֻaֻlawֻisֻconsistentֻwithֻourֻNation’sֻhistori- cal tradition of firearms regulation, we begin by considering whether that lawֻ“addressesֻaֻgeneralֻsocietalֻproblemֻthatֻhasֻpersistedֻsinceֻ[theֻ Founding].” Id. at 2131. If such a problem is apparent but we are unable toֻfindֻ“aֻdistinctlyֻsimilarֻhistoricalֻregulationֻaddressingֻthatֻproblem,”ֻ theֻ“lack”ֻofֻsuchֻaֻhistoricalֻregulationֻisֻ“evidenceֻthatֻtheֻchallengedֻ regulationֻisֻinconsistentֻwithֻtheֻSecondֻAmendment.” Id. “Likewise,ֻifֻ earlier generations addressed the societal problem, but did so through materially different means, that also could be evidence that a modern regulationֻisֻunconstitutional.” Id. That appears to be the case here. Violence at post offices and against postal workers is a general societal problem that even the Postal Service seems to acknowledge existed at— and has existed since—the Founding. The postal system predates our Nation. See U.S. Postal Serv., The United States Postal Service: An Amer- ican History 1–4 (2025 ed.), https://perma.cc/ST55-ZVJKֻ(“Postal Ser- vice History”). The Constitution then granted Congress the enumerated powerֻtoֻ“establishֻPostֻOfficesֻandֻpostֻRoads.” U.S. Const. art. I, § 8, cl. 7. And presumptively because of the ongoing threat to the mail, Con- gressֻsoonֻinferredֻfromֻthisֻenumeratedֻpowerֻanֻ“impliedֻpower”ֻtoֻ “punishֻthose[]ֻwhoֻstealֻlettersֻfromֻtheֻpost-office[]ֻorֻrobֻtheֻmail.” 3 Joseph Story, Commentaries on the Constitution 38 (1833); see also M‘Culloch v. Maryland, 17 U.S. (4 Wheat.) 316, 385 (1819) (explaining inֻ dictaֻ thatֻ “theֻ powerֻ ofֻ establishingֻ postֻ officesֻ andֻ postֻ roads[]ֻ involvesֻthatֻofֻpunishingֻtheֻoffenceֻofֻrobbingֻtheֻmail”). By all appearances, such violence directed toward the postal system and postal workers continued to pose an intractable societal problem throughout the nineteenth and twentieth centuries. See Postal Service History at 17 (describing the dangers to mail carriers of traveling by stagecoach). In 1921, serving as a mail clerk was so dangerous that the postmaster general armed mail clerks with pistols and authorized them to “shootֻtoֻkill.” Id. at 23. And by the 1980s and 1990s, shootings at post officesֻhadֻbecomeֻsoֻcommonֻthatֻ“goingֻpostal”ֻenteredֻtheֻAmericanֻ lexiconֻasֻaֻtermֻforֻ“becom[ing]ֻuncontrollablyֻangry.” 13 13 Austin Harvey, The Chilling Story of the Post Office Shootings that Inspired the Phrase ‘Going Postal,’ AllֻThat’sֻInterestingֻ(Jan. 29, 2025), https://perma.cc/K4CW- 12  Application of 18 U.S.C. § 930(a) to Post Offices Yet Congress had never prohibited carrying firearms specifically in post offices. TheֻFoundingֻgeneration’sֻsolutionֻtoֻtheֻproblemֻwasֻtoֻ impose severe penalties for mail robbery. In 1792, Congress made it a crime,ֻpunishableֻbyֻ“death,”ֻtoֻ“robֻtheֻmailֻ. . .ֻofֻanyֻletterֻorֻpacket,”ֻ toֻ“stealֻsuchֻmail,”ֻorֻtoֻ“stealֻandֻtakeֻ. . . from out of any post-office, anyֻletterֻorֻpacket.” Act of Feb. 20, 1792, ch. 7, § 17, 1 Stat. 232, 237 (“1792ֻAct”). Two years later, Congress made it a crime, again punisha- bleֻbyֻ“death,”ֻtoֻ“robֻanyֻcarrierֻofֻtheֻmailֻ. . .ֻofֻsuchֻmail.” Act of May 8, 1794, ch. 23, § 17, 1 Stat. 354, 361. Several years after that, Congress amended the punishment to a maximum of 40 lashes and 10 years of imprisonment for a first offense, and death for a second of- fense. See Act of Mar. 2, 1799, ch. 43, § 15, 1 Stat. 733, 736. But if a first offenderֻ“muchֻwound[ed]”ֻtheֻmailֻcarrierֻorֻputֻtheֻmailֻcarrier’sֻ“lifeֻ inֻjeopardy[]ֻbyֻtheֻuseֻofֻdangerousֻweapons,”ֻtheֻpunishmentֻremainedֻ “death.” Id. Congress did not impose criminal penalties for carrying weapons into a post office until its general bar on weaponry in federal buildings in the 1980s. Supra Part I. Instead, the Executive Branch was the first entity that restricted firearms in post offices. But even it did not do so until the latter half of the twentieth century. In 1964, it promulgated regulations prohibiting the possession of firearms in federal buildings. See 29 Fed. Reg. 15,972, 15,982 (Dec. 1, 1964); see also Ayala, 711 F. Supp. 3d at 1342. And in 1972, it promulgated regulations prohibiting the possession of firearms in post offices specifically. See 37 Fed. Reg. 24,346, 2,4347 (Nov. 13, 1972); see also Ayala, 711 F. Supp. 3d at 1342. That Congress historically addressed the problem of violence at post officesֻandֻagainstֻpostalֻworkersֻthroughֻ“materiallyֻdifferentֻmeans”ֻ suggests that there is no history or tradition of restricting firearms in post offices. Bruen, 142 S. Ct. at 2131. Since history and tradition is the yard- stick by which the right to keep and bear arms codified in the Second Amendment is measured, this reasoning suggests that section 930(a) is inconsistent with that right as applied to post offices open to the public— as at least two lower courts have found. See Firearms Pol’y Coal. Inc. v. Bondi, 805 F. Supp. 3d 721, 727 (N.D. Tex. 2025); Ayala, 711 F. Supp. 3d at 1341–42. MPZR; see also Scott Williamson, The Surprising Origin of the Phrase ‘Going Postal,’ Grunge (Dec. 14, 2021), https://perma.cc/44FH-E888. 13  50 Op. O.L.C. __ (Aug. 12, 2026) One counterargument is that modern post offices are not analogous to post offices from the Founding era because the latter were not located in government buildings. See Firearms Pol’y Coal., 805 F. Supp. 3d at 729. “Untilֻ theֻ earlyֻ 1900s, . . . the Post Office was [often] located in the postmaster’sֻhomeֻorֻotherֻplaceֻofֻbusiness,ֻsuchֻasֻaֻgeneralֻstore.” U.S. Postal Serv., Sources of Historical Information on Post Offices, Postal Employees, Mail Routes, and Mail Contractors at 14 (2022), https://perma.cc/5YNC-3RCQֻ (“Sources of Historical Information”). Onlyֻ“[a]ֻsmallֻpercentageֻofֻPostֻOffices—fewer than 1 percent before 1910—were located in government-ownedֻbuildings.” Id. It is unclear why this distinction should make a constitutional differ- ence to the question before us. Congressֻwasֻprovidedֻtheֻpowerֻtoֻ“es- tablishֻPostֻOffices,”ֻwithoutֻanyֻrequirementֻthatֻitֻdoֻsoֻonֻpropertyֻ that the federal government owned. U.S. Const. art. I, § 8, cl. 7. And the 1792 law described above made robbing the mail a crime regardless of the fact that many post offices were then located on privately owned land. See 1792 Act § 17, 1 Stat. at 237; Sources of Historical Information at 14. Because many members of Congress were themselves among the Framers of the Constitution, courts typically give considerable weight to such early understandings of the power provided to Congress. See Marsh v. Cham- bers, 463 U.S. 783, 790 (1983). So do we. See, e.g., The President’s Constitutional Authority to Conduct Military Operations Against Terror- ists and Nations Supporting Them, 25 Op. O.L.C. 188, 202 (2001) (rely- ingֻonֻevidenceֻofֻPresidentֻGeorgeֻWashington’sֻunderstandingֻofֻhisֻ constitutional authority to deploy the armed forces abroad). Evenֻifֻweֻwereֻtoֻlimitֻourֻreviewֻtoֻtheֻ“smallֻpercentageֻofֻPostֻ Offices . . . located in government-ownedֻbuildings”ֻatֻtheֻFounding,ֻweֻ would still need to look for some evidence that the government restricted the carrying of firearms in those federal buildings. Sources of Historical Information at 14. We are aware of no such evidence, and at least two courts that have examined the issue have similarly found none. See Ayala, 711 F. Supp. 3d at 1341–42; Firearms Pol’y Coal., 805 F. Supp. 3d at 729–30. Because the government bears the burden of proof at this stage of the Bruen analysis, this lack of evidence alone is enough to give us pause. But consistent with the instructions of Bruen,ֻweֻalsoֻlookֻforֻ“aֻwell- establishedֻ andֻ representativeֻ historicalֻ analogue”ֻ toֻ aֻ firearmsֻ re- striction in post offices. 142 S. Ct. at 2133 (emphasis omitted). 14  Application of 18 U.S.C. § 930(a) to Post Offices b. Even expanding our review to statutes that are relevantly similar to sec- tion 930(a)—rather than historical twins—our doubts are not assuaged. The nearest such analogue that we have been able to locate is the so-calledֻ“sensitiveֻplaces”ֻdoctrine,ֻunderֻwhichֻtheֻgovernmentֻmayֻ restrict the carrying of firearms in certain locations without violating the Second Amendment. See id. Theֻarchetypicalֻ“sensitiveֻplaces”ֻwhereֻ firearmsֻmayֻbeֻrestrictedֻareֻ“legislativeֻassemblies,ֻpollingֻplaces,ֻandֻ courthouses.” Id. Butֻ“theֻhistoricalֻrecordֻyieldsֻrelativelyֻfewֻ18th- and 19th-centuryֻ‘sensitiveֻplaces’ֻwhereֻweaponsֻwereֻaltogetherֻprohibit- ed.” Id. Indeed, the scholarship cited by the Court in referencing this doctrine suggests that the number of Founding-era restrictions at these sensitive places was exceptionally small. See David B. Kopel & Joseph G.S. Greenlee, The “Sensitive Places” Doctrine: Locational Limits on the Right to Bear Arms, 13 Charleston L. Rev. 205, 235–36ֻ(2018)ֻ(“Kopelֻ&ֻ Greenlee”).14 Post offices that are generally open to the public do not appear to be legallyֻanalogousֻtoֻtheֻarchetypicalֻ“sensitiveֻplaces”ֻunderֻtheֻsecondֻ step of the Bruen analysis. 142 S. Ct. at 2133. If we were trying to conclu- sivelyֻ“[d]etermin[e]ֻwhetherֻthisֻconditionֻ[was]ֻmet,”ֻweֻwouldֻneedֻ toֻconsiderֻbothֻtheֻ“how”ֻandֻtheֻ“why”ֻofֻtheֻrelevantֻregulation— “thatֻis,ֻwhetherֻitֻimposedֻaֻrestrictionֻsimilarֻtoֻthatֻimposedֻbyֻtheֻ challengedֻlaw”ֻandֻ“whetherֻitsֻrationaleֻwasֻsimilarֻtoֻthatֻofֻtheֻnewֻ law.” Wolford, 14