15.1 Sexual Offenses Under PA Crimes Code Chapter 31
Key Takeaways
- 18 Pa.C.S. § 3121 Rape is F1; requires sexual intercourse plus forcible compulsion, threat, unconscious/impaired complainant, or complainant under 16 by actor 4+ years older.
- 18 Pa.C.S. § 3123 IDSI is F1 and mirrors Rape but requires deviate sexual intercourse (oral/anal) — a forced oral act is IDSI, not Rape.
- 18 Pa.C.S. § 3122.1 Statutory Sexual Assault is F2 generally but F1 when the complainant is under 16 and the actor is 11+ years older, or under 13.
- 18 Pa.C.S. § 3102 — mistake as to age is generally NOT a defense where age is an element; age is strict liability.
- 18 Pa.C.S. § 3107 — physical resistance by the victim is NOT required; lack of resistance does not equal consent.
Sexual Offenses Under 18 Pa.C.S. Chapter 31
Pennsylvania's sexual offense scheme lives in 18 Pa.C.S. Chapter 31. The MPOETC exam expects you to distinguish graded offenses by their elements, recognize strict-liability age rules, and apply consent/resistance statutes. These offenses are heavily tested because the grading tiers, age-gap mechanics, and Megan's Law registration consequences all overlap.
Core Graded Offenses
The first skill is sorting the five principal offenses by citation, grading, and trigger element.
| Offense | Citation | Grading | Key Element |
|---|---|---|---|
| Rape | § 3121 | F1 | Sexual intercourse by forcible compulsion, threat, unconscious/impaired complainant, or complainant under 16 by actor 4+ years older (involuntary) |
| IDSI | § 3123 | F1 | Deviate sexual intercourse under same forcible-compulsion / impairment / age-gap triggers; IDSI with child under 13 causing serious bodily injury = F1 |
| Statutory Sexual Assault | § 3122.1 | F2 (F1 when age-gap rules apply) | Sexual intercourse with complainant under 16, not spouse, consensual but unlawful age situation; F1 if complainant under 16 and actor 11+ years older, or under 13 |
| Sexual Assault | § 3124.1 | F2 | Sexual intercourse or deviate sexual intercourse without consent, where not covered by rape/IDSI |
| Aggravated Indecent Assault | § 3125 | F2 (F1 against child under 13) | Indecent contact by forcible compulsion, threat, unconscious, impaired, or with complainant under 13/under 16 by much older actor |
| Indecent Assault | § 3126 | M2 (M1 aggravated) | Indecent contact without consent |
| Indecent Exposure | § 3127 | M2 (F3 if minor under 16 present) | Exposure likely to offend/alarm |
Distinguishing Rape from IDSI from Statutory Sexual Assault
The exam repeatedly tests the intercourse vs. deviate sexual intercourse distinction and the forcible-compulsion vs. unlawful-age distinction.
- Rape (§ 3121) requires sexual intercourse and one of the enumerated involuntary triggers: forcible compulsion, threat of forcible compulsion, unconscious/unaware complainant, substantially impaired/mentally incapacitated complainant, or complainant under 16 by an actor 4+ years older.
- IDSI (§ 3123) mirrors Rape but requires deviate sexual intercourse. A forced oral or anal act is IDSI, not Rape — this is a classic exam trap.
- Statutory Sexual Assault (§ 3122.1) applies where the intercourse is consensual but the complainant is under 16 and not the spouse. It is generally an F2, but jumps to F1 when the age gap widens (complainant under 16 and actor 11+ years older, or complainant under 13). Note the overlap: a 19-year-old with a 15-year-old is Statutory Sexual Assault (F2); a 27-year-old with a 15-year-old triggers the F1 age-gap rule.
Street Scenario — DV Call with Statutory Disclosure
You respond to a noise complaint at an apartment. A 22-year-old male answers the door; a 15-year-old female is inside. She states she is his girlfriend and they have been having sex for two months. The male claims she told him she was 17. Under § 3102 Mistake as to Age, his belief about her age is generally NOT a defense — age is a strict-liability element in sexual offenses where the victim's age is an element. Charge § 3122.1 Statutory Sexual Assault; because the actor is only 7 years older, it grades as F2 (not the 11+ year F1 tier). Separately, because she is under 16 and he is 4+ years older, the involuntary prong of § 3121 Rape may also apply — consult the DA.
Consent and Resistance
§ 3107 Resistance Not Required provides that the prosecution need not prove the complainant physically resisted. Lack of resistance does not equal consent, and the absence of physical resistance is not a defense. This statute exists because historic common-law rape required utmost resistance; PA has rejected that rule by statute. The exam may present a fact pattern where a victim froze or was paralyzed by fear — § 3107 controls, and forcible compulsion can be established by threat alone.
§ 3124.1 Sexual Assault is the catch-all for non-consensual intercourse/deviate intercourse that does not meet a Rape/IDSI tier (e.g., no forcible compulsion proven but consent was absent). It grades as F2.
Aggravated Indecent Assault vs. Indecent Assault
The indecent contact offenses track the same trigger structure but at lower grading. § 3125 Aggravated Indecent Assault is F2 generally and F1 when the complainant is under 13. § 3126 Indecent Assault is M2, bumped to M1 in aggravated circumstances. The line is often the age of the complainant or the presence of forcible compulsion.
Indecent Exposure and the Minor Present Aggravator
§ 3127 Indecent Exposure is M2 generally but escalates to F3 when committed in the presence of a minor under 16. If a suspect exposes himself to an adult passerby, it is M2; the same act in view of a 10-year-old is F3.
Megan's Law Registration
Most Chapter 31 offenses trigger sex-offender registration under 42 Pa.C.S. § 9799 (Megan's Law), with tiers (Tier I/II/III) set by offense severity. Rape, IDSI, and Aggravated Indecent Assault against a child under 13 typically drive Tier III (lifetime registration). An MPOETC question may ask which registration tier applies — answer from the offense, not the sentence.
Exam Traps to Memorize
- Mistake as to age is NOT a defense (§ 3102) — strict liability as to age where age is an element.
- Physical resistance is NOT required (§ 3107) — a frozen victim can still prove forcible compulsion.
- Rape vs. IDSI turns on intercourse vs. deviate intercourse — a forced oral act is IDSI.
- Statutory Sexual Assault grades F1 when the age gap hits 11+ years or the complainant is under 13.
- Indecent Exposure escalates to F3 when a minor under 16 is present.
A 28-year-old actor engages in consensual sexual intercourse with a 15-year-old who is not his spouse. What is the correct charge and grading under 18 Pa.C.S. Chapter 31?
A suspect forces a complainant to perform oral sex by holding a knife to her throat. Which offense and grading apply?
On a domestic call, a 19-year-old male states his girlfriend told him she was 17; she is actually 15. They have had consensual intercourse. What is the legal effect of his mistaken belief about her age?