Missouri Weapons Offenses

Unlawful Use of Weapons (§ 571.030)

Missouri’s primary weapons offense statute covers a broad range of conduct:

The “exhibiting in a threatening manner” provision is one of the most commonly charged weapons offenses in the St. Louis area. It often arises from confrontations, road rage incidents, and arguments where a firearm was displayed but never discharged.² The line between lawful self-defense and unlawful exhibition is frequently contested.

Unlawful Possession of Firearms (§ 571.070)

Certain categories of people are prohibited from possessing firearms under Missouri law:

Felon in possession is a Class D Felony — up to 7 years in prison — and it also triggers federal exposure under 18 U.S.C. § 922(g), which carries its own separate penalties.³ Many felon-in-possession cases arise from routine traffic stops or contact with law enforcement for unrelated matters, where the person didn’t realize their prior conviction prohibited firearm ownership.

Armed Criminal Action (§ 571.015)

Armed Criminal Action (ACA) is not a standalone offense — it’s an enhancement that attaches to any felony committed while using, assisting with, or threatening with a dangerous instrument or deadly weapon.⁴ ACA carries:

• Mandatory minimum of 3 years (1st offense) — no probation, no parole
• Mandatory minimum of 5 years (subsequent offense)
• Mandatory minimum of 15 years if the underlying crime is a dangerous felony
• Sentence served consecutively with the underlying felony sentence

ACA is one of the most consequential charges in Missouri criminal law because it stacks on top of whatever other sentence is imposed. A person convicted of assault second degree (up to 7 years) plus ACA (mandatory 3 years consecutive) faces a minimum of 3 years plus whatever the underlying sentence produces — and none of that ACA time is eligible for probation or early release.⁵

We see ACA attached to robbery, assault, drug distribution, burglary, and domestic violence cases throughout the St. Louis area. Fighting the ACA charge is frequently the most impactful defense objective in a weapons case.

Defacing a Firearm (§ 571.080)

Possessing a firearm with an altered, removed, or obliterated serial number is a Class B Felony — 5 to 15 years in prison.⁶ This charge can be brought even if the person wasn’t the one who altered the serial number — mere possession of a defaced firearm is sufficient.

Unlawful Transfer of Weapons (§ 571.060)

Selling, leasing, or transferring a firearm to a person known to be prohibited from possessing one is a Class E Felony.⁷ This includes transfers to convicted felons, fugitives, and persons under disability.

Self-Defense and Castle Doctrine Protections

Missouri provides robust legal protections for the use of force in self-defense:

Castle Doctrine (§ 563.031): A person has no duty to retreat from their own dwelling, residence, or vehicle before using defensive force — including deadly force — against an intruder who has unlawfully entered or is attempting to enter.⁸

Stand Your Ground (§ 563.031): Missouri extends the no-duty-to-retreat principle beyond the home. A person who is lawfully present in any location has no duty to retreat before using force in self-defense if they reasonably believe such force is necessary to protect themselves or another from imminent harm.⁹

Presumption of Reasonableness: When force is used against someone who has unlawfully entered a dwelling, there is a legal presumption that the defender had a reasonable fear of death or serious physical injury.

These protections are powerful — but they don’t apply automatically. The defense must establish the factual predicate: lawful presence, reasonable belief in imminent harm, and proportional response. We build self-defense cases through investigation, witness interviews, physical evidence analysis, and expert testimony when needed.

Defense Strategies for Weapons Charges

Fourth Amendment Challenges

Many weapons cases begin with a traffic stop, a pat-down, or a search of a residence. If the encounter was unconstitutional — no reasonable suspicion for the stop, no probable cause for the search, no valid warrant — the weapon itself may be suppressed as evidence. Without the weapon, the prosecution typically has no case.¹⁰

Self-Defense and Justification

When a weapon was used in self-defense, the defense of justification under § 563.031 can result in a complete acquittal. We investigate the circumstances to establish reasonable belief in imminent harm, proportional response, and all other elements of the self-defense framework.

Challenging “Possession”

In constructive possession cases — where a weapon was found in a shared vehicle, a common area, or a location accessible to multiple people — the prosecution must prove that the specific person charged knew about the weapon and had control over it. Presence alone is insufficient.

Challenging Felon Status

In felon-in-possession cases, the prior felony conviction must be proven. If the prior conviction has been reversed, vacated, or expunged, or if the person’s rights have been restored, the possession charge may not stand.

Fighting Armed Criminal Action

ACA requires proof that a weapon was used, assisted with, or threatened during the commission of a felony. We challenge the connection between the weapon and the underlying offense — demonstrating that mere presence of a weapon doesn’t automatically trigger ACA if it wasn’t used in furtherance of the crime.

Collateral Consequences of Weapons Convictions

Weapons convictions carry consequences that extend far beyond the prison sentence:

Federal firearms prohibition. Any felony conviction permanently prohibits firearm possession under federal law (18 U.S.C. § 922(g)). This applies to all felony weapons convictions as well as domestic violence convictions.

Employment. Weapons convictions — particularly those involving violence — are among the most damaging on background checks. Security clearances, law enforcement, military service, and many other professions become unavailable.

Housing and civil rights. Felony convictions affect voting rights during incarceration and parole, housing eligibility, and professional licensing.

Facing Weapons Charges in St. Louis?

Weapons cases are high-stakes and fast-moving. The difference between a lawful act of self-defense and a felony conviction can come down to the quality of the investigation and the skill of the defense. Constitutional challenges to searches and seizures, self-defense arguments, and challenges to Armed Criminal Action enhancements are all tools we deploy to protect the freedom and rights of people facing these charges.

Call us 24/7 for a free consultation. The defense starts with a conversation.

References

1. § 571.015, RSMo [Armed Criminal Action — 3-year mandatory minimum, consecutive].
2. § 571.030.1(4), RSMo [Exhibiting weapon in angry/threatening manner].
3. § 571.070, RSMo [Unlawful possession by felon]; 18 U.S.C. § 922(g) [Federal prohibition].
4. § 571.015.1, RSMo [ACA — enhancement for any felony with dangerous instrument].
5. § 571.015.2, RSMo [ACA — no probation, no parole, consecutive sentence].
6. § 571.080, RSMo [Defacing firearm identification — Class B Felony].
7. § 571.060, RSMo [Unlawful transfer of weapons].
8. § 563.031.2, RSMo [Castle Doctrine — no duty to retreat in dwelling].
9. § 563.031.3, RSMo [Stand Your Ground — no duty to retreat when lawfully present].
10. U.S. Const. amend. IV; Mapp v. Ohio, 367 U.S. 643 (1961).