9 minimum sentences unless substantial and compelling circumstances are found to exist (s51(1) read with s51(3)(a)). [10] The notional starting point of the enquiry for the two categories of offenders to whom the Act does apply thus differs. For adult offenders the starting point is the minimum sentence prescribed by the legislature. That sentence, which is intended to be a severe and standardised one, may only be departed from if there is weighty justification therefor (S v Malgas 2001 (1) SACR 469 (SCA) para 25). It is for the adult offender to establish that substantial and compelling circumstances justifying a departure are present. [11] For child offenders between the ages of 16 and 18, the sentencing court starts with a clean slate. Subject to the weighting effect of the statutorily prescribed minimum sentences, the sentencing court is free to impose such sentence as it would ordinarily have imposed. It may decide in the exercise of its sentencing discretion to impose the minimum sentence prescribed by s51(2) for an offence of the kind specified in Schedule 2. That a discretion to impose the minimum sentence does indeed exist is clear from the use of the words ‘decides’ and ‘decision’ in s51(3)(b). The sentencing court is called upon in the exercise of its discretion to make a decision as to whether or not to impose the minimum sentence prescribed by the Act. But it is not