Australian Institue of Criminology

Skip to content

Alcohol and assault on Friday and Saturday nights

Findings from the DUMA program

Josh Sweeney and Jason Payne
ISSN 1836-9111
Canberra: Australian Institute of Criminology, May 2011

Abstract

The Australian Institute of Criminology’s DUMA program presents a unique opportunity to examine the prevalence and nature of alcohol consumption by a sample of offenders detained by the police during times consistent with those targeted through Operation Unite. The findings provide valuable insight into the alcohol consumption patterns of assault offenders, illustrating not only that the majority of assault offenders had been drinking prior to their arrest, but that the quantities of alcohol they had consumed were likely to result in high levels of intoxication.

Key findings

  • The AIC interviewed 170 assault offenders detained on Friday and Saturday nights as part of the Drug Use Monitoring in Australia (DUMA) program. Analysis of questions about alcohol use provides valuable information to support a range of alcohol harm reduction strategies, including Operation Unite.
  • Those charged with assault on Friday and Saturday nights were more likely than those charged at other times to have consumed alcohol in the past 48 hours and attribute alcohol as a factor in their offending.
  • Detainees who had consumed alcohol in the past 48 hours and been charged with assault on a Friday and Saturday night were nearly twice as likely as those charged at other times to have been mixing drinks on the last occasion they drank. This was particularly the case for young males aged 18 to 25 years (48%).
  • Assault offenders consumed substantial amounts of alcohol in the lead up to their arrest. The median number of standard drinks consumed by assault offenders was 14, although this was higher for young males who had been mixing drinks on the last occasion they drank (22 standard drinks).
  • Of those who had been drinking, half of all assault offenders consumed their last drink at a residential location. Thirty percent had been drinking at licensed premises. Younger males aged 18–25 years were more likely to have been drinking at a licensed premise.

Introduction

In 2010, the Australian Alcohol Education and Research Foundation (AERF) released its report into the hidden harms associated with alcohol use. A key focus of that report was the not previously estimated, but tangible, costs of alcohol's harm to others, which according to the authors amounted to a total of $14.2b annually. Included in this were costs experienced by those living with or affected by the alcohol use of someone else, such as out of pocket expenses for lost or damaged property, lost wages, hospitalisation and child protection costs. There was an additional estimated $6.4b in annual intangible costs, which included such things as physical or mental health expenses. The AERF report (Laslett et al. 2010) is unique in that for the first time, the impact of alcohol use on others (besides the drinker themselves) has been counted. It is yet another timely reminder of the need for new interventions and strategies for dealing with the consequences of alcohol misuse.

One approach, coordinated by Australian and New Zealand policing agencies, is Operation Unite— a targeted policing initiative that uses a range of strategies, including a highly concentrated and highly visible policing presence around entertainment precincts during peak trading hours on Friday and Saturday nights (SAPOL 2010). Operation Unite has been implemented on three occasions since December 2009, the most recent on 17 and 18 December 2010. Such action is considered an important and justified response to the growing evidence of linkages between alcohol and violence in the night-time economy. For example:

  • an inquiry by the Victorian Parliament's Drugs and Crime Prevention Committee found that 17 percent of assaults in the Melbourne central business district in 2008–09 were recorded by the police as having occurred on licensed premises. Nearly one in three (29%) of the assaults were classified by the police as alcohol-related, including a substantial proportion of incidents that occurred on the street (31%) or in other public spaces (30%; DCPC 2010);
  • a study of assaults near (but not specifically at) licensed premises in New South Wales found that 64 percent of assaults were known to have involved a victim or an offender who had recently exited a licensed venue (Fitzgerald, Mason & Borzycki 2010); and
  • examination of the relationship between alcohol outlet density and assault in New South Wales showed that 37 percent of assaults in the Sydney Local Government Area were recorded by the police within 20 metres of a liquor outlet (Burgess & Moffatt 2011).

Although Operation Unite and other such strategies are underpinned by a growing evidence base, much of this ongoing work relies heavily on information retrieved from official police databases despite their known limitations (eg see DCPC 2010). What is often missing from the debate is quality data that examines who is likely to be involved in alcohol-related assaults, what and how much they had been drinking and where they consumed their last drink. This information could prove useful if policing and other intervention strategies are to have more than just a short-term impact.

To provide this information, the Australian Institute of Criminology's (AIC's) DUMA program presents a unique opportunity to examine the prevalence and nature of alcohol consumption by a sample of offenders detained by the police during times consistent with those targeted through Operation Unite. Currently operating at nine sites across the country (Bankstown, Parramatta, Kings Cross, Footscray, East Perth, Darwin, Brisbane, Southport and Adelaide), DUMA is Australia's longest running quarterly collection of self-reported drug use and offending data from police detainees. Since mid 2009, the DUMA survey has asked a series of new questions about alcohol use, including detailed information about the type and quantity of alcohol consumed, as well as the location of the last drink.

About this study

The present study examined the nature of alcohol consumption by assault offenders detained by the police and interviewed as part of the AIC's DUMA program. Specifically, this included offenders who were detained at any one of nine DUMA interview sites between the hours of 6 pm and 6 am Friday night and 6 pm and 6 am on Saturday night. The interview sites are police watch houses or police stations, so offenders in this particular dataset are people that have either been charged with, or arrested for, the offence of assault. Data collection was conducted over an eight week period each quarter. The hours selected for the study were chosen specifically on the basis that they reflected peak periods for alcohol-related incidents and although they did not coincide directly with Operation Unite, they nevertheless corresponded with the periods typically targeted during the Operation. Further, the data and subsequent analysis provided in this report has been restricted to the 18 months following June 2009, as this was the date at which new and more comprehensive questions on alcohol consumption were introduced into the DUMA survey.

There are a number of limitations that should be considered when interpreting these results. First, DUMA is a voluntary self-report survey of police detainees and like all self-report surveys, the quality of the data hinges on the truthfulness and reliability of the respondents. Second, while it is possible to identify where the respondent consumed their last drink prior to their assault offence, it is not possible to identify where the offence actually occurred as this is not recorded on the DUMA survey. Finally, a small number of detainees charged with assault (n=53) were not interviewed because they were deemed by local watch house staff to have been too intoxicated or violent. Many of these 'out of scope' detainees are also likely to have been drinking alcohol prior to their offence and so the estimates in this report are likely to be conservative. See Drug Use Monitoring in Australia: 2009 Annual Report on Drug Use Among Police Detainees (Sweeney & Payne forthcoming) for further methodological information.

Results

Profile of 'weekend' assault offenders

Between June 2009 and December 2010, 914 assault offenders were detained by the police and interviewed as part of the DUMA program. Of these, 170 were detained between the hours of 6 pm and 6 am on Friday and Saturday nights. The remaining 744 assault offenders were detained at other times throughout the week. Overall, assault offenders comprised 17 percent of the total 5,539 detainees interviewed during the period, whereas on the weekend, assault offenders comprised 21 percent of all those detained on Friday and Saturday nights.

In terms of basic demographics, the single largest group of offenders detained for assault on Friday and Saturday nights were males aged between 18 and 25 years (n=77, 45%), followed by males aged between 26 and 35 years (n=41, 24%) and males aged 36 years or older (n=31, 18%). Overall, only 12 percent of those detained for an assault charge on the weekends were female (n=21), although again, the largest group were those aged between 18 and 25 years (n=10).

In terms of alcohol consumption, nearly three in every four assault offenders had been drinking alcohol in the 48 hours prior to their arrest on Friday or Saturday night (n=118, 70%). Almost half of the offenders charged with assault (n=77, 45%) said that their consumption of alcohol contributed to the offence for which they were detained. This figure rises to 66 percent for those who had been drinking in the previous 48 hours.

Although the numbers are small, there was some evidence that males were more likely than females to have been drinking in the 48 hours prior to their arrest (70% for males versus 62% for females). Further, younger detainees were more likely than older detainees to have been drinking recently, with as many as 79 percent of males aged between 18 and 25 years drinking in the 48 hours prior to their arrest and 53 percent attributing alcohol as a factor that contributed to their arrest.

Table 1: General profile of detainees charged with assault
Charged with assault on Friday and Saturday nightsa
n%
Assault charges 170 19b
Gender
Male 149 88
Female 21 12
Age
18–25 yrs 87 51
26–35 yrs 47 28
36+ yrs 36 21
Alcohol use
Drank in past 48 hrs 118 70
Recent alcohol attribution 77 45

a: Charged with assault on Friday and Saturday nights between the hours of 6 pm and 6 am

b: As a percentage of total assault arrests during the course of a week between June 2009 and December 2010

Source: AIC DUMA collection 2010 [computer file]

Table 2: Alcohol use and attribution, by age in years and gender, of those arrested on Friday and Saturday nights
Males
18–25 yrs26–35 yrs36+ yrs
n%n%n%
Detainees 77 52 41 28 31 21
Recent alcohol use
Drank in past 48 hours 61 79 26 65 18 58
Recent alcohol attribution 41 53 16 39 11 35
Females
18–25 yrs26–35 yrs36+ yrs
n%n%n%
Detainees 10 48 6 29 5 24
Recent alcohol use
Drank in past 48 hours 7 70 3 50 3 60
Recent alcohol attribution 6 60 1 17 2 40

Source: AIC DUMA collection 2010 [computer file]

What were they drinking and how much did they drink?

Since the introduction of a new survey in June 2009, the DUMA program has collected a range of new data items relating to alcohol. Specifically, the new questionnaire asks detainees to nominate whether they had consumed beer, wine or spirits on the last occasion they were drinking and for each type of alcohol, how many units were consumed. A range of counting units is provided to differentiate between various strengths of beer and different serving volumes, making it possible to distinguish between those who consumed six pints (570ml) of low-strength beer from those who consumed four middies (285ml) of full-strength beer and those who drank three glasses (180ml) of wine. This new system not only enables the AIC to distinguish between different types of alcohol, but also to more accurately estimate standardised drinking units (standard drinks).

Of the 105 male assault offenders who had been drinking in the 48 hours prior to being detained on Friday or Saturday night, 18 percent (n=19) had been drinking beer only, 13 percent (n=13) had been drinking wine only and 27 percent (n=28) had been drinking spirits only. The remaining 44 male detainees (42%) had been drinking a mixture of beer, wine or spirits prior to the assault for which they were detained. Female detainees were more likely than males to have been drinking spirits only (62%) and less likely to have been mixing drinks (15%).

By age, younger males aged between 18 and 25 years were those most likely to have been mixing drinks on the last occasion (48%), whereas males aged 36 years and over were those most likely to have been drinking beer only (50%) and least likely to have been drinking spirits only (6%).

In terms of median quantities, detainees typically consumed 14 standard drinks on the last drinking occasion—equivalent to approximately nine schooners (425mls) of full-strength beer. Males consumed a greater number of standard drinks than females (15 standard drinks versus 9 standard drinks), while younger male detainees aged between 18 and 25 years consumed more than their older counterparts aged 36 years and over (16 standard drinks versus 10 standard drinks). These quantities also varied considerably by the type of alcohol consumed; for example, those who mixed drinks on the last occasion drank twice as much (20 standard drinks) as those who consumed beer, wine, or spirits only (10 standard drinks, respectively). Combined, the results indicate the highest quantity of alcohol is typically consumed by young males (18 and 25 years) who are mixing drinks (22 standard drinks).

Figure 1: Last drink type consumed by male detaineesa, by age category (%)

RIP 14 Figure 1

a: For those who had consumed alcohol in the past 48 hours

Source: AIC DUMA collection 2010 [computer file]

Table 3: Standard drinks consumed by those charged with assaulta
Average drinks consumed on the last drinking occasionMale 18–25 yrsMale 26–35 yrsMale 36+ yrsTotal male and female detaineesb
medianmedianmedianmedian
Beer only 11 n/a 10 10
Wine only 10 9 10 10
Spirits only 10 18 n/a 10
Mixed drinks 22 20 n/a 20
Total standard drinks 16 16 10 14

a: For those who had consumed alcohol in the past 48 hours

b: Total median standard drinks for both male and female detainees. For female detainees, totals by age category were too infrequent for inclusion

Source: AIC DUMA collection 2010 [computer file]

Location of last drink

To give further context to the situations in which detainees had been drinking, the DUMA survey also asks detainees to identify the location at which they consumed their last drink (see Figure 2). Overall, the single most common location of last drink in the 48 hours preceding arrest was at a private residential location (53%); most commonly the detainee's own home (30%) or 'other family or friends' home (23%). Of the remaining 47 percent, 30 percent had been drinking most recently at licensed premises, including at a nightclub (11%) tavern or hotel (9%), a services club (8%), or a restaurant (2%). A small number of assault offenders had consumed their last drink at a park or other open space (14%).

The location of last drink varied depending on the age of the offender, with a higher proportion of older offenders drinking in their own home (48%). Conversely, younger assault offenders aged between 18 and 25 years were more likely to have been drinking at licensed premises (34%) or at the homes of other family and friends (25%).

The quantity of alcohol consumed by assault offenders varied, depending on the location of their last drink. For example, those that had their last drink at a residential location typically consumed less (median 12 standard drinks) than those who had been drinking at licensed premises (median 15 standard drinks). Interestingly, however, the group that consumed the highest number of drinks were those whose last drink was on the street or in a public place (median 17 standard drinks).

Figure 2: Location of last drinka for males by age category (%)

RIP 14 Figure 2

a: For those who had consumed alcohol in the past 48 hours

Source: AIC DUMA collection 2010 [computer file]

How do 'weekend' assault offenders compare with other assault offenders?

Compared with those detained for assault at all other times on all other days, other than on Friday or Saturday night, weekend assault offenders were more likely to be younger and to have consumed alcohol shortly before their arrest. For example, those offenders detained for assault at nights on the weekend were more likely be aged between 18 and 25 years (51% for Friday and Saturday night versus 39% for other times of the week), to have consumed alcohol in the 48 hours prior to their arrest (70% versus 50%) and to have attributed alcohol as a factor in their offending (45% versus 28%). Moreover, those detained for assault during the night on weekends were:

  • twice as likely to have been mixing drinks (39% versus 20%);
  • likely to have consumed more alcohol on the last occasion they were drinking (14 standard drinks versus 12 standard drinks)—a difference that was larger when examined for 18 to 25 year old males only (16 standard drinks versus 13 standard drinks); and
  • more likely to have consumed their last drink at a licensed premise (30% versus 19%) compared with those who were arrested and detained for assault at other times throughout the week. This difference was, again, larger for males aged 18 to 25 years (34% versus 20%).

Summary

The cost of alcohol-related harm to the community is considerable and efforts to raise community awareness and reduce alcohol-related crime, such as Operation Unite, are important components to the overall policy response. However, the long-term success of these strategies will be shaped by the quality of the information and research that underpins them and therefore, a variety of data sources are needed to help monitor such contemporary problems and inform policy debates.

In this paper, an analysis was provided of new data collected from assault offenders as part of the AIC's DUMA program, focusing specifically on offenders detained between 6 pm and 6 am on Friday or Saturday nights. DUMA is Australia's only regular collection of information about drug use and offending from police detainees. It presents a unique opportunity to examine, in detail, information that would not normally be available through traditional data sources.

The results show that detainees charged with assault on a Friday and Saturday night are substantially different to those detainees charged at all other times and days of the week. In particular, assault offenders detained over the weekend were more likely to:

  • have consumed alcohol in the 48 hours prior to their arrest (70% versus 50%);
  • attribute alcohol as a factor in their offending (45% versus 28%);
  • be aged between 18 and 25 years (51% versus 39%);
  • have last consumed alcohol at a licensed premise (30% versus 19%);
  • have mixed types of alcoholic drinks (39% versus 20%); and
  • consume a greater quantity of alcohol during the most recent episode of drinking (14 versus 12 standard drinks (median).

Overall, young males aged between 18 and 25 years comprised the single largest group of offenders detained for assault on Friday or Saturday night (45%). Specific analysis by age reveals that young males were not only more likely to have been drinking in the 48 hours prior to their arrest (79%), but were also more likely to report alcohol as a contributing factor in their offending (68% of those that had been drinking). Specifically, young males were more likely to have been:

  • drinking a mix of alcohol types;
  • drinking greater quantities of alcohol—median of 16 standard drinks (although this was as high as 22 standard drinks for those who were mixing alcohol types); and
  • drinking most recently at a licensed premise.

These findings provide valuable insight into the alcohol consumption patterns of assault offenders detained during periods similar to those targeted through Operation Unite, illustrating not only that the majority of assault offenders had been drinking prior to their arrest, but that the quantities of alcohol they had consumed were likely to result in high levels of intoxication. Knowing the profile of assault offenders, the amount of alcohol they have consumed and where they consumed their last drink provides a more detailed picture than previously available of the population targeted by law enforcement agencies. In addition, these data provide important information supporting a range of complementary strategies such as regulatory controls and their enforcement (eg licensing restrictions and mandatory responsible service of alcohol provisions), social marketing campaigns targeting young people and building community awareness of the dangers associated with alcohol misuse.

Table 4: General profile of all detainees charged with assault
Charged with assault on Friday and Saturday nightsaCharged with assault at all other times and days
n%n%
Those charged with assault 170 19 744 81
Gender
Male 149 88 622 84
Female 21 12 122 16
Age
18–25 yrs 87 51 288 39
26–35 yrs 47 28 246 33
36+ yrs 36 21 210 28
Alcohol use
Drank in past 48 hrs 118 70 372 50
Recent alcohol attribution 77 45 210 28
Last drink at a licensed premiseb 35 30 70 19
Last drink at residential locationb 62 53 209 56
Mixed alcoholic drink typesb 46 39 74 20
n median n median
Total detainees who consumed alcohol and standard drinks consumed 116 14 366 12

a: Between the hours of 6 pm and 6 am

b: For those who had consumed alcohol in the past 48 hours

Source: AIC DUMA collection 2010 [computer file]

References

All URLs correct at March 2011

What is DUMA?

DUMA is Australia's only nationwide survey of drug use and criminal offending among police detainees. Funded by the Australian Government, DUMA uses a detailed self-report survey and voluntary urinalysis to provide timely data on drug use and local drug markets. DUMA is an important source of information for local and national law enforcement agencies in the development of strategic responses to new and emerging drug/crime issues.

DUMA data collection occurs every quarter at eight of the nine available sites across the country and operates on a rotating basis. The program operates as a successful partnership between the AIC and state and territory police agencies.

For more information about DUMA, or to access DUMA data and publications, please visit: http://www.aic.gov.au/about_aic/ research_programs/nmp/duma.aspx or email us at: duma@aic.gov.au