(1) Where there are grounds for discretionary mitigation, a penalty of life imprisonment shall be imposed where the offence committed requires a penalty of aggravated life imprisonment; or twenty-five years imprisonment where the offence committed requires a penalty of life imprisonment. Otherwise the penalty to be imposed shall be reduced by up to one-sixth.

(2) In the evaluation of discretionary mitigation the following matters shall be taken into account: background, social relations, the behaviour of the offender after the commission of the offence and during the trial period, and the potential effects of the penalty on the future of the offender. The reasons for any discretionary mitigation are to be stated in the judgement.