Impact of drug law enforcement: An updated systematic review

Professor Lorraine Mazerolle1

1School of Social Science, University of Queensland

Australian drug policy costs more than AUD$1 billion each year, including police services, judicial resources, legal expenses, corrective services, Australian Federal Police, Australian Customs, and Border Force. Nearly two thirds of drug policy expenditure is spent on state and federal law enforcement activities, including both (a) proactive street-level drug law enforcement tactics including third party partnership policing and problem-oriented policing; and (b) a range of reactive, ‘standard’ policing tactics including crackdowns, raids, and buy-busts.

 The Global Policing Database (GPD) was used to update an earlier 2007 systematic review to assess the impact of street-level law enforcement interventions on drug crime and drug calls-for-service. A total of 26 studies (reported in 29 documents) were eligible for the updated review. Of these, 18 studies reported sufficient data to calculate effect sizes. We find that geographically targeted law enforcement interventions are more effective for reducing drug crime than standard, unfocused approaches.  Street-level drug law enforcement approaches that focus on larger problem areas are more effective than approaches that focus on smaller, more micro problem places.


Lorraine Mazerolle is an Australian Research Council Laureate Fellow (2010–2015), a Professor of Criminology in the School of Social Science at the University of Queensland, and a Chief Investigator with the ARC Centre of Excellence for Children and Families over the Life Course (LCC). Her research interests are in experimental criminology, policing, drug law enforcement, regulatory crime control, and crime prevention. She is the Editor-in-Chief of the Journal of Experimental Criminology, past Chair of the American Society of Criminology’s (ASC) Division of Experimental Criminology (2014–2015), an elected Fellow and past president of the Academy of Experimental Criminology (AEC), and an elected fellow of the Academy of the Social Sciences, Australia and the American Society of Criminology (ASC). Professor Mazerolle is the recipient of the 2018 ASC Thorsten Sellin & Sheldon and Eleanor Glueck Award, the 2016 ASC Division of Policing Distinguished Scholar Award, the 2013 AEC Joan McCord Award, and the 2010 ASC Division of International Criminology Freda Adler Distinguished Scholar Award. She has won numerous US and Australian national competitive research grants on topics such as third party policing, police engagement with high risk people and disadvantaged communities, community regulation, problem-oriented policing, police technologies, civil remedies, street-level drug enforcement and policing public housing sites.