Abstract:
Violence is among the primary concerns of communities around the world, and research from many settings has demonstrated clear links between violence and the illicit drug trade, particularly in urban settings. While violence has traditionally been framed as resulting from the effects of drugs on individual users (e.g., drug-induced
psychosis), violence in drug markets and in drugproducing areas such as Mexico is increasingly
understood as a means of gaining or maintaining a share of the lucrative illicit drug market.
Similarly, several Canadian cities have recently experienced a sharp rise in gun violence, and investigations have demonstrated the intimate role that gangs involved in the production and distribution of illegal drugs have played. For many years both Toronto and Montreal have been plagued with drug-related gun violence, and over the last year Vancouver has experienced a surge in gun violence that authorities have attributed to disputes between criminal gangs involved in the illicit drug market. This increase in violence has occurred despite the Canadian federal government’s announcement of a new National Anti-Drug Strategy, which has redoubled emphasis on law enforcement as the primary approach to the illicit drug problem.
In response to the emergence of violence in Canadian cities, provincial and federal leaders have proposed a range of law enforcement interventions aimed at addressing the illicit drug problem. Although many of these strategies, such as mandatory minimum sentences for drug law violations, have been in place in the United States for many years, the scientific evidence to support Canada’s new policy directions has not been articulated, and several prominent groups have indicated that certain proposed interventions may actually increase harm.
Given the growing emphasis on evidencebased policy-making and the ongoing severe violence attributable to drug gangs in many countries around the world, including, more recently, Canada, a systematic review of the available English language scientific literature was conducted to examine the impacts of drug law enforcement interventions on drug market violence. The hypothesis was that the existing scientific evidence would demonstrate an association between drug law enforcement expenditures or intensity and reduced levels of violence.
This comprehensive review of the existing scientific literature involved conventional systematic searching, data extraction and synthesis methods, and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Specifically, a complete search of the English language literature was
undertaken using electronic databases (Academic Search Complete, PubMed, PsycINFO, EMBASE, Web of Science, Sociological Abstracts, Social Service Abstracts, PAIS International and Lexis-Nexis), the Internet (Google, Google Scholar) and article reference lists from date of inception to October 2009.
The initial search captured 306 studies for further analysis. Of these, 15 were identified which evaluated the impact of drug law enforcement on violence: 11 (73%) presented findings from longitudinal studies using regression analysis, 2 (13%) presented theoretical models of drug market responses to drug law enforcement, and 2 (13%) presented qualitative data. Contrary to our primary hypothesis, 13 (87%) studies reported a likely adverse impact of drug law enforcement on levels of violence. That is, most studies found that increasing drug law enforcement intensity resulted in increased rates of drug market violence. Notably, 9 of the 11 studies (82%) employing
regression analyses of longitudinal data found a significant positive association between drug law enforcement increases and increased levels of violence. One study (9%) that employed a theoretical model reported that violence was negatively associated with increased drug law enforcement.
The present systematic review evaluated all available English language published research on the impact of law enforcement on drug market violence. The available scientific evidence suggests that increasing law enforcement interventions to disrupt drug markets is unlikely to reduce drug gang violence. Instead, the existing evidence
suggests that gun violence and high homicide rates are likely a natural consequence of drug prohibition and that increasingly sophisticated methods of disrupting Canadian gangs involved in drug distribution could unintentionally
increase violence. From an evidence-based public policy perspective, gun violence and the enrichment of organized crime networks appear to be natural consequences of drug prohibition. In this context, and since drug prohibition has not achieved its stated goal of reducing drug supply, alternative models for drug control may need to be considered if drug supply and drugrelated violence are to be meaningfully reduced.
