Crown Solicitor's Office

Insights the parity principle

Issued: 8 June 2021

Similar, but different: the parity principle and sentencing related offenders

Li v R [2021] NSWCCA 75

Key points

To successfully challenge severity of sentence on parity grounds, an offender’s sense of grievance about receiving a heavier sentence than a co-offender must be objectively justifiable.

An appellate court will be cautious to intervene where co-offenders were sentenced by the same judge.


The parity principle in sentencing requires like cases to be treated alike, and different cases to be treated differently: Green v The Queen (2011) 244 CLR 462 at [28]. Any difference between sentences imposed upon co-offenders should not give rise to a justifiable sense of grievance or to an objective appearance of injustice. Li provides a useful illustration of the principle.

Li's sense of grievance on parity grounds

In Li, the applicant and his co-offender, Mr Tsang, pleaded guilty to offences of ongoing supply of a prohibited drug (cocaine), contrary to s. 25A of the Drug Misuse and Trafficking Act 1985. The applicant was sentenced to 4 years and 3 months imprisonment, with a non-parole period of 2 years and 9 months. Mr Tsang was sentenced to 3 years and 4 months, with a non-parole period of 2 years.

The applicant contended in the Court of Criminal Appeal (CCA) that he had a justifiable sense of grievance because he received a longer sentence than Mr Tsang. This was because Mr Tsang, as the ‘up-line supplier’, occupied a ‘significantly’ higher position in the criminal syndicate than did the applicant, a ‘money and drug runner’.

Appeal against severity of sentence

Where the same judge has sentenced related offenders, and has recognised the importance of the parity principle and given effect to it, an appellate court will be ‘cautious and not overly willing’ to intervene on the basis of an asserted departure from the parity principle (applying settled principles at [60]).

In Li, the CCA considered that:

  • The same judge sentenced the applicant and Mr Tsang on the same day and had stated that he was mindful of parity principles (at [63]).
  • Each offender played a vital role in the supply ‘hierarchy’. The sentencing judge, having assessed their respective roles and determined that the offending in each case was in the mid-range of objective seriousness, was clearly not satisfied that Mr Tsang was ‘significantly’ further up the hierarchy than the applicant (at [68]). 
  • Mr Tsang had a more compelling subjective case than the applicant. The sentencing judge made findings about Mr Tsang that were not (or could not be) made about the applicant (at [69]). Mr Tsang had no criminal history in Australia, was otherwise of good character, was unlikely to re-offend and was a ‘model prisoner’.
  • The applicant also had a more serious supply prohibited drug charge to be taken into account on a Form 1 than Mr Tsang (at [71]).
  • The CCA found that the differentiation made by the sentencing judge between the applicant and Mr Tsang was well open to his Honour in the exercise of his sentencing discretion (at [72]-[73]).
  • The applicant’s sense of grievance on parity grounds was not objectively justifiable.   

Implications for prosecutors

If the same judge sentences related offenders, preferably at the same time, he or she will be better placed to give overall consideration to the relationship between the objective and subjective features of offenders. As such, the sentence will be less vulnerable to challenge on appeal on parity grounds.


Sarah-jane Morris, Director
02 9497 9390

Katrina Frearson, Senior Solicitor
02 9497 9558

Alexi Polden, Graduate Solicitor
02 9497 9276

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Last updated:

16 Nov 2022

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