People in contact with the criminal justice system

Key findings

  • The consumption of alcohol and other drugs remains more prevalent among people in contact with the criminal justice system than the general population.
  • Prison entrants in 2018 were more likely than the general population to be non-drinkers, however those that did drink were more likely to drink at high risk levels than people in the general community
  • In 2018, more than two-thirds (67%) of prison entrants smoked tobacco daily.
  • In 2017, almost one-in three (30%) police detainees indicated that illicit drug use contributed to their offending.
  • Two-thirds (65%) of prison entrants in 2018 reported using illicit drugs in the 12 months before incarceration.
  • Three-quarters (75%) of police detainees who provided a urine sample in 2015-16 tested positive for a least one drug type.

More information is available in the People in contact with the criminal justice system factsheet.

The criminal justice system is comprised of three parts, the police (investigative element), courts (adjudicative element) and correctional services (corrective element). Information on alcohol and other drug use from each section of the criminal justice system is presented below.


Illicit drug offences (78,167 offenders) and acts intended to cause injury (78,391 offenders) represented the most common principal offences nationally. The number of illicit drug offenders decreased by 4% (2,993 offenders) between 2016–17 and 2017–18 (ABS 2019a). The majority (67%) of illicit drug offenders were charged with the principal offence of possess and/or use illicit drugs (ABS 2019a).


Data from Criminal Courts, Australia for 2017–18 showed that offences for most defendants are finalised in the magistrate’s courts (92% or 545,251 defendants) and of these:  

  • Illicit drug offences accounted for 10% (or 56,638 defendants), of which 63% (35,790 defendants) were possess and/or use illicit drugs. Males accounted for 75% (48,060) of defendants with a primary offence of illicit drugs finalised in the Magistrates’ Courts.
  • Of defendants proven guilty in the magistrates court for a principal offence of illicit drug offences, 7% were given a custodial sentence, but the majority (63% or 30,883 defendants) were sentenced to monetary orders (for example, a fine) (ABS 2019b) (Table S3.57).
  • Between 2016–17 and 2017–18, illicit drug offences decreased by 2% (1,494), the first decrease since 2010–11 (ABS 2019b). Some of the decrease may be the result of ‘lower level’ offences (such as minor drug possession) being diverted from the courts (ABS 2019b).

Corrective services

A snapshot of the adult (aged 18 and over) prison population at 30 June 2018 showed that there were 42,974 Australians in prison. This represents 221 prisoners per 100,000 population and is 4% increase from 2017 (ABS 2018).

Young people under youth justice supervision

On an average day in 2017–18, 5,513 young people aged 10 and over were under youth justice supervision. Most (4,568 or 83%) young people under supervision were supervised in the community, and close to 1 in 5 (18% or 974) were in detention (some were supervised in both the community and detention on the same day). A total of 10,638 young people were supervised at some time during the year (AIHW 2019c).

Young people aged 10–17 under youth justice supervision, from 1 July 2012 to 30 June 2016, were 30 times as likely as the Australian population of the same age to receive an alcohol and other drug treatment service (AIHW 2018).

Tobacco smoking

The National Tobacco Strategy 2012–2018 recognises that prisoners have some of the highest levels of smoking and that smoking is common among groups that are often over-represented in the prison population (IGCD 2012). Recently, there have been a range of smoking bans introduced in Australian prisons and most correctional facilities are now smoke-free (DoH 2016).

Data from the National Prisoner Health Data Collection (NPHDC) showed that rates of smoking among prisoners is substantially higher than in the general community. In 2018:

  • About three-quarters (75%) of prison entrants currently smoked tobacco.
  • Tasmania had the highest proportion of current smokers (90%), followed by South Australia (83%). Queensland (68%) had the lowest proportion.
  • More than two-thirds (67%) of prison entrants smoked tobacco daily (Figure CRIM1).
  • The average age a prisoner smoked their first full cigarette was 14.1 years (AIHW 2019b).

In the general population, findings from the 2016 National Drug Strategy Household Survey (NDSHS) showed that of people aged 14 and over:

  • 12.2% smoked on a daily basis
  • 14.9% were current smokers
  • the average age of their first full cigarette was 16.4 (AIHW 2017).

Alcohol consumption

The risky consumption of alcohol has been found to be strongly associated with adverse outcomes including criminal offending (Fergusson, Boden & Horwood 2013).

Alcohol consumption was common among police detainees, with data from 2017 showing that 33% of police detainees reported consuming alcohol in the 48 hours prior to arrest, down from 41% in 2013–14 (Patterson et al. 2019). On the last drinking occasion, police detainees consumed an average of 12 (mean 17) standard drinks (Patterson et al. 2019).

Prison entrants in 2018 were more likely than the general population to be non-drinkers, however those that did drink were more likely to drink at high risk levels than people in the general community (refer to Box CRIM1 for information on how alcohol related harm is calculated for prison entrants). Specifically:

  • Prison entrants aged 25–44 years were twice as likely to consume alcohol in greater quantities that those the same age in the general community (e.g. 7 or more standard drinks on a usual day of drinking) (AIHW 2019b).
  • During the 12 months prior to prison, 34% of prison entrants consumed alcohol at levels that placed them at high risk of alcohol-related harm (AIHW 2019b).

Prison entrants in the Northern Territory (60%) and Tasmania (40%) were the most likely to be at high-risk of alcohol-related harm, while those in South Australia (58%) and Queensland (35%) were the most likely to report that they do not drink (AIHW 2019b) (Table S3.59).

Box CRIM1: Calculating alcohol-related harm for prison entrants

The proportion of prison entrants who are at risk of alcohol-related harm as determined using questions on alcohol consumption from the WHO’s Alcohol Use Disorder Identification Test (AUDIT) screening instrument. The AUDIT tool alcohol harm risk profile does not align with the NHMRC guidelines and as such the results are not comparable to the general population (AIHW 2019).

Illicit drug use

It is commonly understood that there is a link between the use of illicit drugs and involvement in the criminal justice system. Illicit drug use has been identified as a primary motivating factor in non-violent property offences such as burglary and theft (Kopak & Hoffman 2014).

Data from the 2017 DUMA program indicates that:

  • Three-quarters (75%) of police detainees who provided a urine sample tested positive for a least one drug type.
  • Almost one in three (30%) police detainees interviewed stated that their illicit drug use contributed to their offending (Patterson et al. 2019).

The Illicit Drug Reporting System (IDRS) is an annual survey of regular injecting drug users across Australia. Reports of criminal activity among the national sample, showed that:

  • Two-fifths (41%) had engaged in at least one criminal activity in the preceding month.
  • Drug dealing (26%) and property crime (24%) were the most commonly reported criminal activities.
  • One-third (32%) of the national sample reported being arrested in the 12 months prior to interview, while more than half (56%) reported a lifetime prison history (Patterson et al. 2018).

Overall, two-thirds (65%) of prison entrants reported using illicit drugs in the 12 months before incarceration. The Australian Capital Territory (89%) and Tasmania (86%) have the highest rates of illicit drug use for prison entrants, while South Australia (58%) and the Northern Territory (40%) had the lowest (AIHW 2019b) (Table S3.60).

In contrast, rates of drug use among the general population were substantially lower, with 1 in 6 (15.6%) people aged 14 and over reporting the use of any drug in the past 12 months (AIHW 2017). Differences in the use of individual drug types among these groups are presented in Figure CRIM2.

Health and harms

The NPHDC includes a number of indicators regarding prisoner health and harms. In 2018: 

  • 40% of prison entrants had ever been told they have a mental health disorder (including drug and alcohol abuse).
  • 10% of prison entrants experienced ‘a lot’ of distress due to alcohol, tobacco and other drug use, while 17% experienced ‘a little’ (AIHW 2019b).

Further, data from the National Prison Entrants’ Blood Borne Virus and Risk Behaviour Survey in 2013 found that almost 1 in 5 (18%) prison entrants had shared injecting drug equipment in the previous month, placing them at risk of communicable disease (Kopak & Hoffman 2014 as cited in AIHW 2015). Less than 1 in 10 (8%) prison dischargees reported using a needle and syringe that had been used by someone else, while in prison (AIHW 2019b).


In terms of treatment, referral episodes from police or court diversion programs accounted for 15% of episodes for clients receiving treatment for their own drug use in 2017–18 (AIHW 2019a). The NPHDC also found that opioid substitution treatment (OST) was currently being undertaken by 7% of prison entrants and 7% of prison dischargees. Around 1 in 7 (13%) prison entrants reported ever having been on an OST (AIHW 2019b).


ABS (Australian Bureau of Statistics) 2019a. Recorded crime – Offenders, 2017-18. ABS cat. no. 4519.0. Canberra: ABS. Viewed 15 March 2019.

ABS 2019b. Criminal courts, Australia, 2017-18. ABS cat. no. 4513.0. Canberra: ABS. Viewed 28 February 2019.

ABS 2018. Prisoners in Australia, 2018. ABS cat. no. 4517.0. Canberra: ABS. Viewed 5 April 2019.

Australian Institute of Health and Welfare (AIHW) 2015. The health of Australia’s prisoners 2015. Cat. No. PHE 207. Canberra: AIHW. Viewed 2 February 2018.

AIHW 2017. National drug strategy household survey 2016: detailed findings. Drug statistics series no. 31. Cat. no. PHE 214. Canberra: AIHW. Viewed 14 December 2017.

AIHW 2018. Overlap between youth justice supervision and alcohol and other drug treatment services: 1 July 2012 to 30 June 2016. Cat. no. JUV 126. Canberra: AIHW. Viewed 16 October 2018.

AIHW 2019a. Alcohol and other drug treatment services in Australia 2017–18: key findings. Web Report. Viewed 17 April 2019.

AIHW 2019b. The health of Australia’s prisoners 2018. Cat. no. PHE 246. Canberra: AIHW. Viewed 30 May 2019.

AIHW 2019c. Youth justice in Australia 2017–18. Cat. no. JUV 129. Canberra: AIHW. Viewed 16 July 2019.

DoH (Department of Health) 2016. Prisoners and recently released prisoners. Canberra: Australian Government. Viewed 2 February 2018.

Fergusson DM, Boden JM & Horwood LJ 2013. Alcohol misuse and psychosocial outcomes in young adulthood. Result from a longitudinal birth cohort studied to age 30. Drug and alcohol dependence 133:513-9.

Intergovernmental Committee on Drugs (IGCD) 2012. National Tobacco Strategy 2012-2018. Viewed 2 February 2018.

Kopak AM & Hoffman NG 2014. Pathways between substance use, dependence, offense type, and offense severity. Criminal Justice Policy Review. 25(6): 743:760.

Patterson, E Sullivan, T, Ticehurst, A & Bricknell, S 2018. Drug use monitoring in Australia: 2015 and 2016 report on drug use among police detainees. Statistical Reports Number 4. Canberra: Australian Institute of Criminology. Viewed 31 May 2019.

Patterson, E Sullivan, T, & Bricknell, S 2019. Drug use monitoring in Australia: Drug use among police detainees, 2017, Statistical Reports Number 14. Canberra: Australian Institute of Criminology. Viewed 18 April 2019.

Peacock A, Gibbs D, Sutherland R, Uporova J, Karlsson A, Bruno R, Dietze P, Lenton S, Alati R, Degenhardt L & Farrell M 2018. Australian Drug Trends 2018. Key findings from the National Illicit Drug Reporting System Interviews. Sydney, National Drug and Alcohol Research Centre UNSW.