Sentencing of Mr Harris will raise similar consideration to those in the Stuart Hall case - previous post of 19th June 2013. It will be recalled that Mr Hall - now aged 84 - was convicted of 14 counts of indecent assault committed in the period 1967 to 1985/6. Following the Attorney-General's undue leniency application to the Court of Appeal, Mr Hall's sentence was increased to 30 months imprisonment. Mr Hall later faced 19 further charges but was convicted on two of them - see the sentencing remarks of Turner J dated 23rd May 2014. For those, he was sentenced to an additional 30 months imprisonment.
of ANY offender is a difficult exercise and the general factors in the Criminal Justice Act 2003 Part 12 apply together with any guidelines issued by the Sentencing Council and any relevant Court of Appeal decisions. The general factors in the 2003 Act include considerations of the purposes of sentencing, the seriousness of the offending, the culpability of the offender and any mitigation. A particularly important Court of Appeal decision in this context is R v H and others  EWCA Crim 2753. This requires sentence to be passed according to the law as it was at the time of the offence and not as it is at the date of sentence. The maximum sentences in relation to historic sex offences are set out in Annex C to the Sexual Offences Definitive Guideline.
An excellent discussion of this guideline is by Felicity Gerry (now QC) on the UK Criminal Law Blog 18th December 2013 - Sentencing Historic Sexual Offences - The new Guidelines. The same blog contains a discussion of some general points relating to Historic Sexual Abuse Allegations
On the specific case of Mr Harris, for a detailed analysis see the UK Criminal Law Blog - Rolf Harris guilty of 12 counts of indecent assault. That post concludes by asking:
As part of the sentencing, Sweeney J will undoubtedly address ancillary orders including the possibility of (a) awarding compensation to victims (though this can be left to civil claims), (b) a Sexual Offences Prevention Order (particularly if the judge considers that there is risk of further offending), and Notification Requirements (Sexual Offences Act 2003 sections 80-92).
Daily Mail 1st July - Rolf Harris and how secrecy betrays justice