"When considering the relevant adult guideline, the court may feel it appropriate to apply a sentence broadly within the region of half to two thirds of the adult sentence for those aged 15 – 17 and allow a greater reduction for those aged under 15. This is only a rough guide and must not be applied mechanistically. In most cases when considering the appropriate reduction from the adult sentence the emotional and developmental age and maturity of the child or young person is of at least equal importance as their chronological age."
"6.1 There will be occasions when an increase in the age of a child or young person will result in the maximum sentence on the date of the finding of guilt being greater than that available on the date on which the offence was committed (primarily turning 12, 15 or 18 years old). 6.2 In such situations the court should take as its starting point the sentence likely to have been imposed on the date at which the offence was committed. This includes young people who attain the age of 18 between the commission and the finding of guilt of the offence but when this occurs the purpose of sentencing adult offenders has to be taken into account, which is: •the punishment of offenders; •the reduction of crime (including its reduction by deterrence); •the reform and rehabilitation of offenders; •the protection of the public; and •the making of reparation by offenders to persons affected by their offences. 6.3 When any significant age threshold is passed it will rarely be appropriate that a more severe sentence than the maximum that the court could have imposed at the time the offence was committed should be imposed. However, a sentence at or close to that maximum may be appropriate."
"The individual factors relating to the offence and the [offender] are of the greatest importance and may present good reason to impose a sentence outside of this range."