Research Summary - Measuring Illicit Cannabis Seizures in Canada

Research Summary - Measuring Illicit Cannabis Seizures in Canada PDF Version (108 Kb)

Current cannabis seizure data must be interpreted with caution, especially when using data from different sources.


Whenever there is a change in policy, it is important to collect information on metrics that will be used by researchers and policy makers to examine the impact of the policy. Legalization of the recreational use of cannabis is a historic policy change for Canada. It is vitally important to have a properly set up system of collection of seizure-based data, both pre- and post-legalization, in order to determine what impact the regime change has had on society. Good seizure-based cannabis metrics are one of the major elements required for studying the cannabis market in terms of use, diversion, grey and black markets, organized crime activity and econometric estimates. In the example of the State of Colorado, where the recreational use of cannabis was legalized in 2012 and the full implementation of the policy occurred in 2014, very little data was collected pre-legalization as well as some time after the legalization.


The report titled “Cannabis Performance Metrics for Policy Consideration: What do we Need to Measure?” (Maslov et al., 2016) served as a background paper to the current project. The project involved a thorough literature review and examination of the relevant performance metrics that can be applied to the upcoming legalization of the non-medical use of cannabis. This consisted of academic published material, documents originating from governments and law enforcement agencies, and grey literature such as newspaper articles, police training material, and non-academic discussion pieces in OECD countries.

This paper was further informed by the results of consultations led by the Canadian Centre for Justice Statistics (CCJS) with the members of the Canadian Association of Chiefs of Police (CACP) Police Information and Statistics (POLIS) Committee on cannabis-related metrics that are possible to collect through police jurisdictions in Canada. Other experts consulted included the Royal Canadian Mounted Police (RCMP) and Canada Border Services Agency (CBSA) colleagues who are either performing the seizures themselves, or work in the research and policy areas relevant to seizures; Health Canada (HC) colleagues who have expertise in cannabis seizures and the specifics of the functioning of Drug Analysis Service (DAS) laboratories; Canadian Police College (CPC) instructors who teach the courses on drug investigative techniques; and, with Public Safety Canada (PS) policy colleagues who are working with the RCMP units who perform seizures of cannabis.


By tracing the transfer and location of cannabis seizure data, it was possible to identify the potential sources for cannabis seizure data, as well as what each database is able to inform.
Four major databases keep data on seizures:

Drug seizures may not always come to the attention of one centralized enforcement authority, such as the RCMP. Therefore, it is understood that no single enforcement authority has accurate data on the amount of cannabis seized across Canada.  Authorization to destroy all seized illicit substances and record this information in a HC database is required under the Controlled Drugs and Substances Act (CDSA). The CDSD is able to provide details on the quantity of seized cannabis (quantity indicated in the same manner as it was seized, in kg or L) that has been sent for destruction, as well as the number of plants seized. According to experts at HC, it is estimated that most seized illicit cannabis is sent for destruction and reported to HC. Therefore, the CDSD can be considered the most comprehensive database on cannabis seizures.

There are currently no mechanisms or direction to ensure that reporting methodologies between departments are consistent. While cannabis seizures are carried out fairly consistently across organizations, the reporting process varies within and between organizations. As a result, cannabis seizure data cannot be used to gather an accurate representation of the magnitude of the cannabis market in Canada. Taking steps to ensure greater consistency would increase the reliability of data and of the analysis. Cannabis is a drug that is found in varied forms, increasing the difficulty in developing guidelines on how to treat cannabis systematically.

Experts have highlighted the need to interpret all cannabis seizure data with restraint because of the importance of context in the case of each seizure. Raw data on cannabis seizures mean little without robust analysis of the context of cannabis seizures and how it fits into the context of the drug market in Canada.

Data accessibility was one of the biggest challenges in the collection and analysis of seizure metric data. More consistent reporting between agencies and with the public is needed. A number of specific areas for potential opportunities were identified such as: data linkages, system interoperability, centralization, partnerships, and data reconciliation.


While Canada is undergoing a historic process of legalizing the recreational use of cannabis, it is important to remember that the illicit market for cannabis may not entirely disappear post-legalization. It will be important to consider the role cannabis seizure data will continue to play under a different regime. Current seizure metrics by existing partners may need to be adapted as we move from gathering baseline data towards understanding the impact and context over time. Data from sources outside of the current cannabis seizure enforcement model may need to be supplemented by data from administrative or regulatory sources, which will require new partnerships, potentially introducing new concerns or highlighting existing ones for data sharing.


Mawani, F., Maslov, A., & Lawrence, A. (2017). Measuring Illicit Cannabis Seizures in Canada: Methods, Practices, and Recommendations. Public Safety Canada: Ottawa.

Additional Sources

Maslov, A., Lawrence, A., and Ferguson, M. (2016). Cannabis Performance Metrics for Policy Consideration: What Do We Need to Measure? Public Safety Canada: Ottawa.

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Research Summaries are produced for the Community Safety and Countering Crime Branch, Public Safety Canada. The summary herein reflects interpretations of the report authors' findings and do not necessarily reflect those of the Department of Public Safety Canada.

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