Comparative rates of violent crime amongst methamphetamine and opioid users: Victimisation and offending

Research Summary no. 32

Michelle Torok, Shane Darke, Sharlene Kaye, Joanne Ross, Rebecca McKetin

Plain English summary and implications for police prepared by Roger Nicholas.

Aims and Methodology

The project aimed to determine the prevalence and types of violent crime perpetrated by, and upon a sample of methamphetamine users. The project also sought to determine the circumstances leading to this crime and the factors that predicted it. These fi ndings were compared with those obtained from a sample of heroin users. A sample of 400 regular methamphetamine and heroin users from the greater Sydney region were interviewed. The sample was categorised into three key groups based on whether they primarily used methamphetamine or heroin, or were users of both methamphetamine and heroin. The researchers measured levels of physical violence such as assault (including sexual assault), armed robbery and homicide.

Key findings

  • There was a high prevalence of violent offending among the illicit drug users. Eighty two percent had ever committed a violent crime, 74% had ever committed more than one violent crime and approximately 40% had violently offended in the past 12 months.
  • The primary methamphetamine users were more likely to have committed a violent crime in the past year than were the primary heroin using group (51% versus 35%).
  • Methamphetamine use signifi cantly increased the risk of violent offending in the past 12 months, particularly more frequent methamphetamine use. The increased risk of violent offending associated with methamphetamine use was consistent across a number of indicators.
  • While the majority of these violent incidents occurred among drug user networks, particularly among males, a signifi cant proportion were also of a domestic nature. Almost one in five of the methamphetamine and the methamphetamine / heroin users had assaulted a police officer.
  • Apart from methamphetamine use, other factors that were found to increase the risk of committing violent offences were heavier alcohol use, having a conduct disorder, selling drugs, and being younger.
  • Across the whole sample, 95% had ever been a victim of violence, and nearly half (46%) had experienced victimisation in the past 12 months. The overwhelming majority had been victimised on multiple occasions. Methamphetamine use was not a significant risk factor for violent victimisation.
  • The major factors infl uencing violent victimisation among illicit drug users were severity of alcohol use, a predisposition towards antisocial behaviour, and drug dealing.
  • Being involved in illicit drug markets substantially increased the risk of victimisation.
  • The majority of the sample perceived that it would be ‘unlikely’ or ‘very unlikely’ that they would be either a victim of violence (78%) or a violent offender (87%) in the following 12 months, despite the high prevalence of violent victimisation and offending experienced in the previous 12 months.

Implications for policing

The current study indicates that violence is a major problem among illicit drug users. The study confi rms police perceptions that methamphetamine use is associated with higher levels of aggressive behaviour. The study also highlighted the signifi cant occupational, health and safety hazards which police face when responding to violent incidents which involve substance use, particularly those which involve methamphetamine. The study also found that the violence described by the illicit drug users was often of a serious nature, involving high levels of weapon use and often requiring medical intervention. Despite high levels of public concern regarding the risk of drug-related violent victimisation, the majority of violent incidents occurred among drug user networks, particularly amongst males.

Methamphetamine users are unpredictable, a large proportion have psychotic symptoms, and many are susceptible to an agitated delirium which leads to violent behaviours. Unsurprisingly, psychostimulants are one of the most commonly detected classes of illicit substances found amongst homicide offenders and victims. Therefore, in dealing with methamphetamine users, it is important that police are aware of the high potential for pharmaceutically-induced violence, even amongst street-level users not involved in dealing networks.

Reducing the supply of methamphetamine in Australia could reduce the overall level of societal violence and potentially even homicide rates.

Diversion into drug treatment programs remains an important option for problematic methamphetamine users. At present, those methamphetamine users who have a history of violence may be being precluded from diversion programs, despite the fact that treatment could successfully reduce methamphetamine-induced violence. This is an issue that warrants closer consideration.

A substantial proportion of violence perpetrated by the methamphetamine users was of a domestic nature. This was particularly relevant to females, who were more likely than males to assault their partners, and to be assaulted by them. As is evident in many cases, both partners in a relationship will be methamphetamine users. This also raises issues about the risks to the children of methamphetamine users. The impact of methamphetamine use on family violence is currently little understood and warrants further investigation.