Evaluation of decriminalizing small amounts of illicit drugs in Victoria, BC: A seasonally adjusted interrupted time-series analysis of police data.

BACKGROUND

In 2023, British Columbia (BC), Canada implemented a three-year pilot policy to decriminalize personal possession of a cumulative total of 2.5 g or less of opioids, cocaine, methamphetamine, and MDMA. Under this exemption, individuals found within the threshold are not subject to criminal charges, though possession above 2.5 g, possession in excluded locations (e.g., schools, airports), and trafficking remain criminal offences. This study evaluates the impact of this policy on police-reported drug-related offences, charges, and seizures in Victoria, BC.

METHODS

Interrupted time-series analysis used police administrative data from the Victoria Police Department between January 2020 and December 2023. Monthly rates of drug-related offences, charges and seizures per 100,000 adults aged 15+ were analyzed across three policy phases: pre-announcement (run-in), policy awareness, and post-implementation. Autoregressive integrated moving average and mixed linear regression models were used to adjust for trend, seasonality and repeated measures.

RESULTS

Offences and charges declined during the period prior to the implementation of decriminalization, but not during the decriminalization pilot. The mean weight of drugs seized per incident increased significantly post-implementation, but rates and proportions of seizures with cumulative drug weights <4.5 grams declined.

CONCLUSION

Enforcement shifts preceded formal decriminalization, possibly reflecting anticipatory changes in policing practices. The post-implementation increases in seizure weights, alongside declining low-weight seizures, may indicate a reallocation of enforcement away from personal possession. To strengthen the impact of decriminalization, future efforts should prioritize clear policy communication, implementation training, and alignment between enforcement practices and public health goals.