18 U.S.C. § 2441 has no statute of limitations, which means that a war crimes complaint can be filed at any time. .
http://www.globalresearch.ca/index.php?context=viewArticle&code=20051028&articleId=1159Article 1
No statutory limitation shall apply to the following crimes, irrespective of the date of their commission:
(a) War crimes as they are defined in the Charter of the International Military Tribunal, Nurnberg, of 8 August 1945 and confirmed by resolutions 3 (1) of 13 February 1946 and 95 (I) of 11 December 1946 of the General Assembly of the United Nations, particularly the "grave breaches" enumerated in the Geneva Conventions of 12 August 1949 for the protection of war victims;
(b) Crimes against humanity whether committed in time of war or in time of peace as they are defined in the Charter of the International Military Tribunal, Nurnberg, of 8 August 1945 and confirmed by resolutions 3 (I) of 13 February 1946 and 95 (I) of 11 December 1946 of the General Assembly of the United Nations, eviction by armed attack or occupation and inhuman acts resulting from the policy of apartheid, and the crime of genocide as defined in the 1948 Convention on the Prevention and Punishment of the Crime of Genocide, even if such acts do not constitute a violation of the domestic law of the country in which they were committed.
http://www.unhchr.ch/html/menu3/b/p_limit.htm