Criminal jurisdiction

Criminal jurisdiction is a term used in constitutional law and public law to describe the power of courts to hear a case brought by a state accusing a defendant of the commission of a crime. It is relevant in three distinct situations:

Under the public international law system, de jure states are sovereign within their own territorial boundaries. A few states such as the Netherlands have adopted a monist approach, i.e. they accept international and municipal laws as part of a single system. Thus, whether a supranational court or tribunal has criminal jurisdiction over its territory or citizens, will be determined by international law. The majority of states are dualist, i.e. they will only accept international obligations through the process of incorporation, say by signing and adopting treaties and conventions. Hence, whether a supranational court or tribunal will have jurisdiction and, if so, over what subject matter and over what period of time, will be decided by the sovereign government of the day.

Because each government is supreme, it can enact whatever statutes it wishes. Thus, State A would have the power to make a law which, for example, made it an offence to smoke in the streets of State B, a neighbouring state. State A could employ officers and equip them with cameras. These officers could then collect evidence in State B and, when its citizens returned home, State A could prosecute them for breach of the law. But State A's law could not be directly effective in State B because that would make State B less than sovereign. Similarly, State A could not seek the extradition of its own citizens from State B unless State B was formally to consent (usually through the negotiation of a treaty including the particular offence).

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