The term ‘international criminal law’ is merely a useful way of describing those aspects of international law that are concerned with crimes having an international aspect or dimension. We will first look briefly at mutual legal assistance in criminal matters and extradition, and then at international crimes and how international law seeks to deal with them. (Terrorism is dealt with in Chapter 14.)

Mutual legal assistance

Although only a tiny number of criminal cases have an international element, the few that do are often serious in nature. The greater ease with which people now travel abroad means that the authorities of a state investigating or prosecuting a crime may need the help of other states, who may also have an interest. Depending on the law and procedure of the requested state, assistance may be given on an informal basis. The association established by national police forces to exchange criminal intelligence, Interpol, may be used. Within the European Union, the European Police Office (Europol) plays a similar role.