PART II
PUNISHMENT OF OFFENDERS UNDER THE CONVENTIONS AND PROTOCOL I
3. Punishment of grave breaches of the Conventions and Protocol I
3. (2) The penalty for an offence under subsection (1) is—
(a) where the offence involves the wilful killing of a person protected by the relevant Convention or by Protocol I, the penalty for murder; and
(b) in any other case, imprisonment for life.
National penalties - war crimes
National penalties - national proceedings
EDIT.