The campaign and the subsequent Japanese occupation of Singapore included war crimes committed against captive Allied personnel and civilians, such as the Alexandra Hospital and Sook Ching Massacres. Yamashita's culpability for these events remains a matter of controversy, as some argued that he had failed to prevent them. However, Yamashita had the officer who instigated the hospital massacre and some soldiers caught looting executed for these acts, and he personally apologised to the surviving patients.
From 29 October to 7 December 1945, an American military tribunal tried General Yamashita for war crimes relating to the Manila Massacre and sentenced him to death. This case has become a precedent regarding the command responsibility for war crimes and is known as the Yamashita Standard. The trial was especially controversial.