Military sex offense law under the UCMJ covers a dozen or more distinct crimes spread across six different sections of the code. Contact offenses allege physical sexual conduct and are prosecuted under Article 120 for adults, Article 120b for children, and Article 134 for sexual harassment. A single incident can produce half a dozen overlapping charges, and the table below shows what the government has to prove for each one. Conduct that doesn’t look sexual on its face can still be charged as a sex offense under Article 120, like hazing. In many sexual assault cases, and some cases involving minors, an accused might be able to mount a defense based on an honest mistake about consent or age. OSTC, the military’s congressionally-mandated elite prosecution corps, controls charging, and that’s where the former JAGs of Gagne, Scherer & Associates begin working the case, before charges are even preferred. And four 2026 sexual assault decisions show how often the prosecutors, judges, and appellate courts who run this system get the law wrong.
Contact Offenses: Articles 120, 120b, and 134
Contact offenses allege physical sexual conduct, not just rape. Article 120 covers adults. Article 120b covers children (anyone under 16). Article 134 covers sexual harassment, which can involve physical conduct but isn’t a registerable sex offense.
The table below shows the contact offenses and what the government has to prove.
Contact Sex Offenses Under the UCMJ: Key Differences
| Offense | Article | What the Government Must Prove |
|---|---|---|
| Rape (adult) | 120(a) | You forced someone to have sex through violence, threats of death or serious injury, making them unconscious, or drugging them |
| Sexual assault without consent | 120(b)(2)(A) | You had sex with someone who didn’t agree to it |
| Sexual assault: sleeping/unconscious victim | 120(b)(2)(B) | You had sex with someone who was asleep or unconscious, and you knew or should have known they were out |
| Sexual assault: incapacitated victim | 120(b)(3)(A) | You had sex with someone who was too drunk or drugged to consent, and you knew or should have known it |
| Aggravated sexual contact | 120(c) | You groped someone under the same circumstances that would make penetration rape, had there been penetration: by force, threats, drugging, or making them unconscious |
| Abusive sexual contact | 120(d) | You groped someone who didn’t agree to it, was asleep, or was too drunk to consent |
| Rape of a child (under 12) | 120b(a)(1) | You had sex with a child under 12. No force required. The act alone is enough. |
| Rape of a child (12–15, by force) | 120b(a)(2) | You had sex with a child between 12 and 15 using force, threats, drugging, or making them unconscious |
| Sexual assault of a child | 120b(b) | You had sex with a child between 12 and 15. No force required. |
| Sexual abuse of a child | 120b(c) | You committed a sexual or indecent act on or in the presence of a child under 16, including sexual touching, exposure, or indecent language |
| Sexual harassment (not a sex offense) | 134 | You made unwelcome sexual advances or engaged in unwelcome sexual conduct severe or repetitive enough to create a hostile environment, with a connection to the military |
What the Table Doesn’t Tell You
The table explains what differentiates the crimes under the law. Here’s what you need to know about how these laws work in real cases:
- The three Article 120 sexual assault theories (without consent, sleeping/unconscious, incapable of consenting) all carry the same maximum punishment but require proof of different facts. The government can charge all three for the same incident.
- Article 120b child offenses don’t require proof of lack of consent.
- For children under 12, the offense is “strict liability” when it comes to age. Mistake of fact about the child’s age is no defense. For children 12 to 15, the accused can raise a reasonable belief that the child was 16 or older.
- “Groped” is used here to mean any unlawful sexual contact.
- Sexual harassment under Article 134 became a separate chargeable offense in 2022. It is a covered offense under OSTC’s purview, but it isn’t a registerable sex offense.
Another thing these tables don’t show is how conduct that doesn’t look sexual can become a sex offense under the UCMJ. Think of them as stealth sex offenses. A testicle twist on the obstacle course. A nut tap in line at the chow hall. Hazing by humping a private area through the clothes. If the government can prove the act was done with intent to abuse, humiliate, harass, or degrade, it fits the statutory definition of sexual contact and can be charged as abusive sexual contact under Article 120. And keeping intimate images from a prior teenage relationship: the day you turn 18, those files from a teenage girlfriend become CSAM under federal and military law.
The Mistake of Fact Defense in Military Sex Cases
Mistake of fact comes up in two contexts under military sex offense law: belief in consent and belief of age.
For proving consent in Article 120 adult cases, the accused can argue that he honestly and reasonably believed the victim consented. The belief has to be both “honest” and “reasonable”: you believed it at the time, and a reasonable, sober person would have too. The law doesn’t punish genuine mistakes.
If you’ve been dating someone for six months, you know how she initiates, how she says no, what her body language looks like when she’s into it and when she’s not. A judge or panel can consider that history when deciding whether your belief in consent was reasonable. But the facts of the specific incident can override all of it (verbal or physical resistance, too drunk, etc).
When it comes to age in Article 120b child cases, a mistake of fact about a child’s age is no defense at all for children under 12. For children 12 to 15, the accused can argue a reasonable belief that the child was 16 or older, but the accused carries the burden of proving it. Context is everything. You meet a young-looking girl in a bar that checks IDs at the door, it’s reasonable to believe she’s at least 21. You meet that same girl at the beach, and she mentions getting her driver’s permit tomorrow, it doesn’t matter how old she looks.
OSTC’s Role in Prosecuting Sex Offenses
Every offense is a “covered offense” under OSTC’s mandate, which means the Office of Special Trial Counsel controls charging decisions. OSTC prosecutors decide whether a case goes to a general court-martial or gets sent back to the command for a lesser disposition.
OSTC’s focus is its winning percentage. They’re evaluating whether the evidence supports a high likelihood of conviction, not just whether probable cause exists. That evaluation creates an opportunity for the defense, before and during the preliminary hearing process. Gagne, Scherer & Associates advocates with OSTC during the investigation phase, before charging decisions are made, and works to put favorable evidence and weaknesses in the government’s case in front of the prosecutors who will decide whether to go forward.
Even Judges Misunderstand UCMJ Sex Offense Laws
If you’re struggling to understand the differences between these offenses, you’re not alone. The prosecutors who write the charges, the judges who oversee the cases, and the appellate courts that review trials are struggling with the same thing.
In January 2026, CAAF issued three opinions on the same day correcting the Air Force Court of Criminal Appeals on how prosecutors try to prove lack of consent when the victim was asleep or intoxicated: United States v. Moore, United States v. Hennessy, and United States v. Serjack. A fourth case from the Army CCA threw out part of a conviction because the military judge’s verdict was too muddled to review (United States v. Williams-Clark, sentence reduced from seven to five years). Prosecutors picked Article 120 theories that didn’t match their facts, lower courts misapplied the precedent, and a trial judge issued a verdict nobody could decipher. Alcohol was at the center of all four cases. In Article 120 UCMJ sexual assault cases, memory, alcohol, and cognitive bias are frequently misunderstood by everyone in the courtroom.
Some defense counsel will read these opinions, think they see a similar mistake in their own case, and waive the Article 32 hearing to preserve a charging defect, gambling that the government won’t notice. But the government will notice. Waive your preliminary hearing and OSTC will wonder why and take a fresh look at its charge sheet and fix it one way or another. Your lawyer will have traded the best chance to derail the case for a technicality that won’t survive. Never waive your Article 32 unless you’re getting a concrete benefit in writing that’s greater than what you could have gotten through a preliminary hearing.
Gagne, Scherer & Associates: Experienced Military Lawyers
Article 120 and 120b cases produce some of the longest sentences in the UCMJ and the most aggressive charging behavior from OSTC. The differences between these offenses look small on a chart and play out as decades of confinement at trial. If you’re under investigation or facing charges for any offense covered on this page, contact Gagne, Scherer & Associates at (224) 935-6172. You’ll speak with an experienced military lawyer, not a paralegal, not a receptionist.
Primary Legal Sources
- 10 U.S. Code § 920b – Art. 120b. Rape and Sexual Assault of a Child. Legal Information Institute, Cornell Law School.
- United States v. Moore, No. 25-0110. United States Court of Appeals for the Armed Forces. Decided January 23, 2026.
- United States v. Hennessy, No. 25-0112. United States Court of Appeals for the Armed Forces. Decided January 23, 2026.
- United States v. Serjak, No. 25-0120. United States Court of Appeals for the Armed Forces. Decided January 23, 2026.