Punishment of grave breaches of Conventions and Protocol I
2. (5) If a court is satisfied that substantial and compelling circumstances exist which justify the imposition of a lesser sentence than the sentence prescribed in subsection (4)(a), it must enter those circumstances on the record of the proceedings and may thereupon impose such lesser sentence.
Sentencing - national proceedings
Determination of sentence - national proceedings
Mitigating factors - national proceedings
EDIT.