## Facts

- A special tribunal was established to prosecute those responsible for the 14 February 2005 Beirut attack killing Rafik Hariri and others, plus certain connected attacks within its jurisdiction.
- Before deciding whether to confirm an indictment, the Pre-Trial Judge referred 15 abstract questions of law to the Appeals Chamber under the tribunal’s rules.
- The referred questions concerned the applicable law for: (1) terrorism, (2) intentional homicide and attempted homicide, (3) conspiracy, (4) perpetration and other modes of liability (including co-perpetration and related doctrines), and (5) cumulative charging.
- The Appeals Chamber addressed these questions without making findings about specific defendants or the evidentiary record.

## Issues

1. Whether terrorism in time of peace is recognized under customary international law and how that affects the tribunal’s application of Lebanese terrorism provisions.
2. What objective and subjective elements define terrorism for purposes of the tribunal’s jurisdiction.
3. Whether intentional homicide and attempted homicide should be interpreted purely under Lebanese law or also in light of international sources.
4. Whether conspiracy is a substantive offense within the tribunal’s jurisdiction and how it differs from group-liability doctrines used as modes of responsibility.
5. What modes of liability (including co-perpetration, indirect perpetration, and group-based liability) are available and how legality limits their use.
6. When cumulative charging is permitted and how to prevent impermissible multiple punishment for the same conduct.

## Decision

- The Appeals Chamber issued an interlocutory decision resolving the referred legal questions in the abstract to guide further proceedings.
- It held that customary international law recognizes a distinct crime of terrorism in time of peace and used that conclusion to interpret the applicable Lebanese terrorism offense.
- It defined terrorism for tribunal purposes by requiring: (1) commission of a criminal act typically involving serious violence or damage; (2) special intent to spread terror among the population or coerce a national or international authority; and (3) a transnational element within the tribunal’s framework.
- It held that intentional homicide and attempted homicide are primarily Lebanese offenses, interpreted with reference to general criminal-law principles drawn from both Lebanese and international sources.
- It held that conspiracy is a substantive crime (punishing the agreement itself) and is conceptually distinct from group-liability doctrines that attribute responsibility for completed crimes carried out under a common plan.
- It approved use of both Lebanese and compatible international modes of liability, including co-perpetration and indirect perpetration, subject to legality and foreseeability.
- It permitted cumulative charging (including terrorism with homicide, and conspiracy with group-based participation theories), while requiring safeguards against double punishment at the conviction and sentencing stages.

## Legal Principles

- Domestic criminal provisions within the tribunal’s mandate may be construed in harmony with relevant international instruments, customary international law, and general principles of law where consistent with legality.
- Customary international law supports a peacetime terrorism offense defined by (1) a serious underlying criminal act and (2) special intent to terrorize a population or coerce an authority.
- Legality (nullum crimen, nulla poena sine lege) requires that crimes and liability theories be sufficiently accessible and foreseeable at the relevant time.
- Terrorism may function as a compound offense built on underlying crimes (e.g., homicide) plus an added special-intent element, permitting distinct legal characterization.
- Conspiracy is an inchoate substantive offense centered on an agreement to commit a crime; group-liability doctrines are modes of liability that attach to completed crimes committed pursuant to a common plan.
- Cumulative charges may be pleaded when each charge contains materially distinct elements or protects distinct legal interests, but convictions and sentences must avoid duplicative punishment for the same conduct.

## Conclusion

The Appeals Chamber clarified the tribunal’s applicable law by recognizing a customary international definition of peacetime terrorism and using it to interpret the relevant domestic offense, while also defining conspiracy, confirming compatible perpetration doctrines, and allowing cumulative charging subject to legality and double-punishment constraints.


Prosecutor v. Ayyash, Case No. STL-11-01/I (Special Trib. Lebanon App. Ch. 2011)