In February 1999, the Ontario Provincial Police received a tip that Walter Tessling was running a marijuana grow operation.

In the course of the investigation, the police checked with Ontario Hydro for significant amounts of electricity usage, often indicative of a grow operation, on Tessling's property.

Without any warrant, the Royal Canadian Mounted Police (RCMP) flew over Tessling's property with a Forward Looking Infra-Red ("FLIR") camera and got a heat profile of the land.

The issue before the Supreme Court was whether the use of a thermal imagery such as the FLIR camera violates the right against unreasonable search and seizure.

The Court held that the thermal imagery did not violate the accuser’s right to be free from unreasonable search and seizure, with Iacobucci and Arbour JJ abstaining.