4 (3) The definitions in this subsection apply in this section.
...
"genocide” means an act or omission... as such, that, at the time and in the place of
its commission, constitutes genocide according to customary international law or
conventional international law or by virtue of its being criminal according to the general principles of law recognized by the community of nations, whether or not it constitutes a contravention of the law in force at the time and in the place of its commission.
EDIT.