Genocide and crimes against humanity are the same as almost every other crime, in that a conviction requires proof beyond a reasonable doubt (or similar standard in the relevant lexicon of the jurisdiction) that a prohibited act (actus reus or "objective element") was carried out by the accused with the appropriate degree of fault (mens rea or "subjective element"). The international crime of genocide specifies five prohibited acts committed against a national, racial, ethnic, or religious group that need to be proved. The fault element requires proof that the act was committed with the intention of destroying the particular group in whole or in part. Crimes against humanity require proof that certain acts were carried out in the context of a widespread or systematic attack against the civilian population. The fault element requires proof that the accused participated in the act in the knowledge that it formed part of the...