The Supreme Court Rules on What the Crown Must (and Must Not) Prove in Impaired Driving Cases
On November 14, 2025, the Supreme Court of Canada (SCC) delivered its judgment in R. v. Larocque, 2025 SCC 36, a companion case to R. v. Rousselle, 2025 SCC 35. This ruling clarifies the Crown’s evidentiary burden when prosecuting the “80 and over” offence, focusing specifically on how much information about the alcohol standard used in breath testing must be proven at trial.
The case revolved around Stéphane Larocque, who was stopped at a sobriety checkpoint and subsequently charged with operating a motor vehicle with a blood alcohol concentration (BAC) equal to or exceeding 80 mg percent. At trial, the Crown introduced certificates from the qualified technician and two analysts to satisfy the preconditions required to utilize the statutory presumption of accuracy in s. 320.31(1) of the Criminal Code.
The issue before the SCC was technical but highly significant: Must the Crown prove the specific numerical target value of the alcohol standard used during the system calibration check to benefit from the presumption of accuracy for breath sample analysis results?
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