The courts must develop a coherent set of sentencing principles, according to law lecturer and barrister Tom O'Malley.
Such principles should be animated by the principle of proportionality, and based on the gravity of the offence and the personal circumstances of the accused.
Mr O'Malley told the prosecutors' conference there was a long way to go in creating such a coherent set of principles, but it was vital that the courts, assisted by lawyers, did so to avoid a further drift towards mandatory sentences.
The development of such principles would be assisted by legal arguments around sentencing following the conviction of the accused.
"The time has now probably come for prosecuting counsel to take a more active role at the sentencing stage of a trial. It is not being suggested that they should make suggestions to the court as to the nature or the amount of punishment to be imposed. In fact, they should emphatically not do that. What they can do is to draw the court's attention to any aggravating factors in the case, and any relevant legislation and case law.
"There is much to be said for a practice whereby each side would furnish the trial judge with a short sentencing memorandum so as to ensure that all relevant factors are considered before sentence is imposed."
The DPP, James Hamilton, said the question of sentencing had come to the fore since the DPP was given the right to seek a review of sentences in serious cases if they appeared to be unduly lenient.
In the last four years the number of reviews sought had consistently been between 20 and 26 out of 2,325 indictable cases heard. Around 60 per cent had been "successful" in that the sentence had been increased, while in others the court said there had been a departure from principle but declined to increase the sentence because of the time elapsed.
The DPP's office had published guidelines on how prosecuting counsel should approach sentencing.
"It is clearly stated in the guidelines that it is part of the duty of prosecuting counsel to draw the trial judge's attention to any relevant case law on sentencing, and to ensure the court is aware of the range of sentencing options available to it. Secondly, it is counsel's duty to lead any evidence which is relevant to sentencing, and this includes aggravating as well as mitigating factors."