Why was Homma Masaharu tried after World War II?

Homma Masaharu, the Japanese lieutenant general who commanded the invasion of the Philippine Islands during World War II, was tried by a U.S. military commission in Manila following the war's conclusion.12

He was formally charged with bearing responsibility for the Bataan Death March, a brutal forced march of approximately 76,000 American and Filipino prisoners of war that resulted in thousands of deaths. Additionally, Homma was held accountable for condoning widespread atrocities and abuses that occurred at Camp O’Donnell, where many captives subsequently died from starvation and disease.12

Following his conviction for ordering the march and permitting these war crimes, Homma was executed by a firing squad on April 3, 1946.12