Practice Relating to Rule 157. Jurisdiction over War Crimes
Peru’s IHL Manual (2004) defines the term aut dedere aut judicare as:
The principle that any State party to the Geneva Conventions is under the obligation to search for persons alleged to have committed, or to have ordered to be committed, any of the grave breaches defined by the law of armed conflict. Accused persons must be brought before the competent courts and, if found guilty, sentenced by such courts to the penal sanctions provided by law.
Peru’s IHL and Human Rights Manual (2010) states:
IHL imposes on States the obligation to search and punish all persons who have committed grave breaches [of IHL], irrespective of the nationality of the perpetrator or the place where they committed the crime. This obligation stems from the principle called UNIVERSAL JURISDICTION … , and includes the obligation to prosecute them or to extradite them. This obligation falls on all States affected by the commission of the crime.
In its Glossary of Terms, the manual also states:
Judicare aut dedere
: Principle based on which every State Party to the  Geneva Conventions has the obligation to search persons accused of having committed or ordered the commission of any of the grave breaches defined by the law of armed conflict. Accused persons must be brought before the competent courts and, if found guilty, sentenced by such courts to the penal sanctions provided by law.
Peru’s Military and Police Criminal Code (2010), under the heading “Universal jurisdiction”, states: “Regarding crimes included in the present Title [namely crimes committed in states of emergency and in violation of international humanitarian law], this Code applies also if they were committed abroad and do not have any link to the national territory.”