18 USC § 931 — The Federal Body Armor Baseline, Explained

Every state body armor law in the United States operates on top of a single federal statute: 18 USC § 931. If you're a seller figuring out compliance or a buyer figuring out eligibility, this is where it starts.

The statute

18 USC § 931 prohibits any person convicted of a crime of violence from purchasing, owning, or possessing body armor in interstate or foreign commerce.

"Body armor" (§ 931(c)) — any product sold or offered for sale in commerce as personal protective body covering intended to protect against gunfire, whether worn alone or as a complement to another product or garment.

The definition is broad: soft armor, plate carriers with ballistic plates, rifle plates, and combined configurations all qualify. Helmets and shields are regulated separately under different standards.

Who's prohibited

Per § 931(a), a person convicted of a felony that is:

1. A crime of violence (as defined in § 16), or
2. A state-law offense that would constitute a crime of violence under § 16 if it occurred within federal jurisdiction

Note: non-violent felons are NOT prohibited under federal law. If a state extends the prohibition to all felons (Connecticut, Kentucky, Louisiana, New Jersey all do), that's state law adding on top of the federal floor.

What "crime of violence" means post-Dimaya

In 2018, the Supreme Court decided Sessions v. Dimaya, striking down the "residual clause" of 18 USC § 16(b) as unconstitutionally vague. After Dimaya, only the "elements clause" of § 16(a) applies:

§ 16(a): An offense that has as an element the use, attempted use, or threatened use of physical force against the person or property of another.

This narrowed the scope of federal body armor prohibition. Offenses that historically might have been classified as crimes of violence via the residual clause (e.g., some non-violent burglaries, some drug offenses with enhancement) may no longer qualify.

Practical effect: the federal floor is narrower today than procurement departments often assume. Sellers relying solely on federal 18 USC § 931 attestation are compliant in a narrower scope than they may realize.

The affirmative defense — § 931(b)

There's a built-in exception for armed guards and similar roles:

§ 931(b): It shall be an affirmative defense that the defendant obtained prior written certification from the defendant's employer that the defendant's purchase, use, or possession of body armor was necessary for the safe performance of lawful business activity, and that the use and possession by the defendant were limited to the course of such performance.

Two conditions:

1. Written employer certification before purchase/possession
2. Use limited to the course of the performance

This exception allows convicted felons to lawfully possess body armor in narrow circumstances — e.g., an armed security guard whose employer has certified the need, using the armor on duty only.

What this is NOT

• Not a self-defense exception for private citizens
• Not a "I need it for protection" argument
• Not an across-the-board "you can have armor if you want it" exception

Penalties

Per 18 USC § 924(a)(7): up to 3 years imprisonment plus a fine under 18 USC § 3571.

Seller vs. buyer obligations

Federal law puts the obligation on the buyer

§ 931 prohibits the purchase, ownership, or possession by prohibited persons. Sellers are not federally required to verify buyer criminal history. The prohibition is on the buyer's end.

However: best practice and state law strongly motivate seller KYC.

Best-practice seller KYC

1. Purchase attestation — signed (or clicked) statement that the buyer is not prohibited under § 931
2. Identity verification — government-issued ID
3. OFAC / sanctions screen — redundant for body armor but trivial to implement
4. Shipping address verification — residential vs. agency; flag inconsistencies
5. Transaction record retention — 7+ years (federal audit standard for comparable regulated sales)

State add-ons

Several states do impose seller obligations beyond federal:

• New York (Exec. Law § 144-a) — seller must verify eligible profession before sale to NY resident
• DC (DC Code § 7-2502) — seller must verify DC professional category
• Connecticut (CGS § 53-341b) — seller must ensure face-to-face transfer for CT residents

Where state law imposes a seller obligation, federal § 931 compliance is necessary but not sufficient.

Interaction with state law

Federal § 931 does not preempt state law. States may (and several do) impose additional restrictions. States may not relax the federal floor — a state cannot "un-prohibit" body armor for federally-prohibited persons.

Three patterns of state extension:

1. Broader felon prohibition (CT, KY, LA, NJ) — any felony, not just violent
2. Profession-gated sale (NY, DC) — eligible profession required
3. Face-to-face required (CT) — no mail-order to residents

(Some states overlap — CT both extends the felon prohibition and requires face-to-face.)

Enforcement pattern

§ 931 is rarely charged alone. Typical pattern: a defendant is arrested for an underlying violent crime while wearing or in possession of body armor; § 931 is charged as an added count to strengthen the case or support plea leverage.

The statute plays a bigger role in civil compliance — BVP grant eligibility, state procurement award decisions, corporate due diligence — than in standalone criminal enforcement.

Practical scenarios

Scenario: small agency buyer

Armed state/local LE agency buying armor for officers. Federal § 931 is satisfied because officers are armed forces / peace officers. No individual officer attestation needed at the purchase transaction; agency procurement handles compliance.

Scenario: civilian in a standard-tier state

Ohio resident, no felony history, buys a concealable vest from an online seller. Attests to § 931 compliance at checkout. Federal baseline satisfied. No state law adds additional restrictions.

Scenario: ex-felon armed guard

Texas armed security guard with a past (non-violent) felony conviction. Under federal § 931 post-Dimaya — if the conviction wasn't a "crime of violence" under § 16(a) — he's not federally prohibited. State law may still restrict (Texas does not). Employer certification under § 931(b) provides the belt-and-suspenders defense.

Scenario: Connecticut civilian

Connecticut resident with no felony history wants to buy armor online. Federal § 931 satisfied. But Connecticut state law (CGS § 53-341b) requires face-to-face sale. Online seller cannot ship direct to CT residential address; buyer must arrange partner retailer pickup.

What Armor Systems does

The federal § 931 baseline is encoded in our compliance engine as the default attestation, applied to every civilian purchase regardless of state. State-specific overlays (NY § 144-a, DC § 7-2502, CT § 53-341b, broader-felon attestations for KY/LA/NJ) layer on top. When the attestation is insufficient (e.g., a red-flag mismatch triggers optional background check), we escalate to enhanced KYC.

References

• 18 USC § 931 — https://www.law.cornell.edu/uscode/text/18/931
• 18 USC § 16 — Crime of violence definition (post-Dimaya: only § 16(a) applies)
• Sessions v. Dimaya (2018) — struck down § 16(b) residual clause
• 18 USC § 924(a)(7) — penalties for § 931 violations
• State body armor statutes — additive to federal; see the state map