## Facts

- Defendants participated in an anti-nuclear protest at the Shippingport Power Plant in Beaver County, Pennsylvania.
- They ignored a visible “No Trespass” sign, went under a perimeter fence, and sat holding hands on plant property.
- A plant security guard and a deputy sheriff ordered them to leave or face arrest; they refused and remained seated.
- Deputy sheriffs removed the defendants and charged each with criminal trespass.
- No injuries or property damage occurred; the plant was in a two-week shutdown at the time.
- Defendants sought to present expert testimony to support a justification defense under 18 Pa.C.S. § 503, asserting nuclear power and radiation risks and claiming the trespass was necessary to avert a greater harm.
- The trial court excluded the proffered justification evidence and declined to instruct the jury on justification; the jury convicted all defendants.
- The Superior Court reversed, holding defendants were entitled to present the justification defense and receive a jury instruction.
- The Commonwealth appealed to the Supreme Court of Pennsylvania.

## Issues

1. Whether 18 Pa.C.S. § 503 (“choice of evils” justification) is available in a criminal trespass prosecution arising from a political protest at a nuclear power plant.
2. Whether the defendants’ offer of proof established a prima facie justification defense requiring admission of supporting evidence and a jury instruction.

## Decision

- The Supreme Court of Pennsylvania reversed the Superior Court and reinstated the judgments of sentence.
- The court held that § 503 can apply to criminal trespass in principle, but the defense is narrowly confined.
- The court concluded the defendants’ proffer did not make out a prima facie case because the asserted harms were not sufficiently immediate, the trespass lacked a direct causal relationship to avoiding the harm, and lawful alternatives remained available.
- The trial court therefore did not err in excluding the justification evidence or refusing the requested jury instruction.

## Legal Principles

- Section 503 provides a limited justification for otherwise criminal conduct only when the actor reasonably believes the conduct is necessary to avoid a greater harm, no specific statutory defense applies, and no legislative purpose plainly excludes the claimed justification.
- A necessity-type justification requires a concrete, impending harm rather than generalized, speculative, or policy-level concerns.
- The defendant must show a direct causal nexus between the unlawful act and the avoidance of the threatened harm; symbolic or communicative protest typically fails this requirement.
- The defense is unavailable when lawful avenues to address the asserted harm remain realistically available; a defendant must show more than disagreement with the effectiveness of legal alternatives.
- Section 503 does not provide immunity for civil disobedience undertaken to advance moral or political objectives.

## Conclusion

The court held that anti-nuclear protesters convicted of criminal trespass could not invoke § 503 because their proffered evidence did not show an imminent harm their trespass would directly avert, nor that lawful alternatives were unavailable; accordingly, the trial court properly withheld the justification instruction and excluded justification-only expert evidence.


Commonwealth v. Capitolo, 498 A.2d 806 (Pa. 1985)