Research into practice brief 2

What works in the policing of street-level cannabis markets? Katie Willis

One important objective of street-level drug law enforcement is to disrupt drug supply within local drug markets. Research evidence indicates that street-level illicit drug markets can be effectively disrupted by police, with the degree of disruption largely dependent on how open or closed the market is. Open markets are generally place and time specific. That is, they operate in a particular location at a certain time of the day. In contrast, closed markets often occur where access to the market is via known or trusted participants and where exchanges are not necessarily bound by a particular location or time. Australian street-level cannabis markets largely reflect the second of these broad types of drug markets (Willis 2008).

So what are the most effective policing strategies that could be applied to intervene in street-level cannabis markets? There is now a significant body of work that addresses the effectiveness of enforcement activity concerning illicit drug markets. In a major review of international evaluation literature concerning the effectiveness of drug law enforcement strategies, Mazerolle et al (2007) found that policing strategies varied considerably in their effectiveness. Overall, interventions found to be effective in dealing with street-level illicit drug markets were proactive in orientation, rather than reactive.

Proactive policing strategies include (but are not limited to):

  • problem-oriented policing (interventions developed with consideration to the underlying problem);
  • third-party policing (which involves police recruiting civilians and other non-police agents to assist in crime prevention activities);
  • drug diversion (diverting eligible drug offenders away from formal criminal justice processes into drug education and treatment); and
  • drug nuisance abatement strategies (this includes use of city codes and ordinances, or non-criminal penalties, to address neighbourhood safety issues. Drug nuisance abatement strategies often feature in problem-oriented or community policing approaches).

These strategies contrast with reactive policing strategies, which include the use of traditional drug law enforcement tactics like (for example) arrests, crackdowns, raids and seizures. Mazerolle et al found that reactive policing strategies were not effective when used as the sole means of suppressing a drug market. However, if reactive strategies were used in combination with proactive strategies then disruption to street-level markets was found to be more effective (Table 1).

Strategies used by police to effectively intervene in open markets are not necessarily appropriate or effective for addressing closed markets. For instance, it is highly unlikely that police strategies used to suppress an open-air heroin market (like a crackdown or drug sweep) would be effective in disrupting a closed cannabis market that operates among friends and acquaintances in private dwellings. Mazerolle et al found that the most effective policing strategies for dealing with closed, indoor markets, such as the street-level cannabis market, included drug nuisance abatement, third-party policing, and civil remedies.

Earlier evaluation work by the United Kingdom s Home Office (Jacobson 1999) found that there are six important elements to successful preventive initiatives against street-level drug markets. While this work is now more than 10 years old, it still has relevancy and provides some useful insights for Australian drug law enforcement. Importantly, findings from the evaluation reflect the same types of strategies found to be effective by Mazerolle et al. In brief, these are:

  • appropriateness of the intervention analysis of a drug market location, prior to the design of a preventive strategy, should include careful examination of the parameters and nature of the local problem. Consultation with residents and community groups can assist to identify unique features;
  • intensity of the intervention combining proactive and reactive enforcement tactics permits the weaknesses of certain approaches to be counteracted by the strengths of others;
  • leverage encouraging potential partners to work with them in addressing local problems by ensuring that potential partners recognise that they have common interests and goals;
  • sustained action it is likely that the beneficial impacts of initiatives will erode over time. Preventive strategies should include elements that have some long-term effects upon local drug market locations, and should be sufficiently flexible to respond to changing patterns of behaviour among drug dealers and users;
  • sensitivity to community relations crime control initiatives that exacerbate existing tensions within neighbourhoods may be counter-productive. When local residents and community organisations are involved in the development of strategies, efforts should be made to include representatives of as many segments of the population as possible; and
  • evaluation thorough process evaluations of initiatives should capture design and implementation problems as and when they arise, and may therefore assist with their resolution. Evaluations should also prevent early mistakes from re-occurring and achievements built upon in later operational phases. Evaluation plays an important role in facilitating the dissemination of good practice.

Table 1

Evidence of effectiveness of police strategies

Source: Adapted from Mazerolle et al 2007


Findings from these and other studies indicate that simplistic approaches to the policing of street-level cannabis and other illicit drug markets (that is, police interventions that focus on the use of one or two tactics only) are unlikely to be effective either in the short or long term. In particular, the use of reactive policing strategies, when used as the only means of intervening in a drug market, are ineffective. Rather, police need to combine both proactive and reactive strategies, as well as consider the degree to which the market is open or closed, to maximise their impact on street-level cannabis markets.


  1. Jacobson, J. (1999). Policing drug hot-spots. Police Research Series Paper 109. London: Police Research Group, Home Office.
  2. Mazerolle, L., Soole, D. & Rombouts, S. (2007). Drug law enforcement: A review of the evaluation literature. Police Quarterly 10, 115-153.
  3. Willis, K. (2008). Cannabis supply into and within Australia. Criminal Justice Series Bulletin 2. Sydney: National Cannabis Prevention and Information Centre.
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