The comments above about the duty of confidentiality refer equally to expert reports sought for the purpose of tender in submissions on sentence. If an independently-requested report is unfavourable or is disputed by the defendant, defence counsel can refrain from tendering the report, although they must not mislead the Court by misrepresenting its contents. If the report has been ordered by the Court itself, the duty solicitor will need to confront the disputed aspects as instructed.
Leniency in sentencing may be appropriate in a case where a person suffers a illness or mental impairment. Any such illness or impairment should be explained to the Court in submissions on a plea of guilty. Where there is some causal connection between the mental illness or impairment and the commission of the offence, the degree of moral culpability may be diminished, such as where the person has a low level of intellectual functioning beyond the person’s control [see Paparone v The Queen (2000) 112 A Crim R 190;  WASCA 127 for causal connection; R v Verdins (2007) 169 A Crim R 581; VSCA 102 for effect of psychiatric illness on sentencing].
The principle of rehabilitation is given considerable weight in such cases and the duty solicitor should put to the court details of any treatment, counselling, or beneficial change in medication which has occurred since the date of the offence [see Mason-Stuart v R (1993) 61 SASR 204;  SASC 4322].
General deterrence as a sentencing principle may have little or no relevance in determining the sentence where the defendant suffers a mental illness or impairment [see Mason-Stuart v R (1993) 61 SASR 204;  SASC 4322; R v Scognamiglio (1991) 56 A Crim R 81]. The rationale is that it would contribute little to the deterrence of the general public by making an example of a defendant suffering from a mental illness or impairment.
However, where the Court is asked to sentence a defendant as a person of diminished responsibility due to mental impairment, the Court will scrutinize the degree of causal connection between the mental illness or impairment and the criminal conduct itself - the defendant’s understanding of the criminality of the conduct. In cases where the Court is not persuaded that the illness had a significant degree of contributing impact on the defendant’s conduct, the Court will normally give the usual weight to general deterrence (see R v Wiskich (2000) 207 LSJS 431;  SASC 64).
Personal deterrence is a relevant sentencing principle, and the Court may consider that a defendant has forfeited a claim to leniency by persistent offending. In some cases the court may feel that a term of imprisonment may in itself have a rehabilitative effect on a person suffering a mental illness [see R v Ciccone (1974) 7 SASR 110]. Defendants with mental health problems often have significant prior histories of similar offending. For this reason the duty solicitor should always approach a guilty plea for such defendants with great caution because a term of imprisonment will always be a potential outcome for reasons of personal deterrence. Where recommended treatment has been disregarded by a defendant in the past, or is unlikely to be successful, the Court may give particular weight to the principle of personal deterrence, and consider it appropriate to impose a sentence of imprisonment [see Webber v Creek (1975) 10 SASR 378].
A court cannot impose “preventative detention” or impose an excessive term of imprisonment merely because a defendant would be a danger to society if they remained in the community [see Veen v R (1979) 143 CLR 458 ;  HCA 7].
Imprisonment should not be imposed as a cure for alcoholism [see Gollan v Samuels (1973) 6 SASR 452]. Where an addiction to gambling has led to dishonesty offending to feed a habit, it is generally viewed as a form of mental impairment which may warrant leniency where the defendant has taken steps towards rehabilitation by participating in counselling and/or by making compensation to the victim. However, in SA Police v John (1995) 181 LSJS 20, where the offending was aggravated by a breach of trust, the mental illness or impairment was not accepted as excusing the offence. Gambling is not accepted as a mental illness per se as yet, and so is considered to have little mitigatory effect upon the sentence [see R v Do (2007) 180 A Crim R 338;  VSCA 308; R v Huynh (2008) 180 A Crim R 517;  NSWCCA 16; R v Grossi (2008) 183 A Crim R 15;  VSCA 51; Thai v DPP (No 3)  SASC 97 - gambling may be considered a mitigating factor where combined with a psychological condition].