The court ruled that adults have a "legitimate expectation of privacy" to possess an ounce of cannabis, which is legal for adults in Colorado. Because the drug-sniffing dog in this case couldn't differentiate for officers whether it had sniffed out cannabis or an illegal drug such as cocaine or heroin, the court decided that the officers needed more evidence than solely a dog's signals before they could search a vehicle.
The ruling stems from a 2015 Moffat County case in which Kevin McKnight was pulled over by Craig Police officer Bryan Gonzales after McKnight left a house known for drug activity, according to Colorado Court of Appeals documents. Here's how the court documents describe what happened:
"At Officer Gonzales’ request, Sergeant Folks came to the scene with his certified drug-detection dog, Kilo. Kilo is trained to detect cocaine, heroin, ecstasy, methamphetamine, and marijuana. He indicates that he has detected the odor of one of these substances by exhibiting certain behavior — barking, for example. His indicative behavior, however, does not vary based on the particular substance or amount of the substance he has detected.The Moffat County District Court convicted McKnight on possession of drug paraphernalia and possession of a controlled substance. The judge presiding over the case allowed evidence found in the search to be used in court despite a motion by McKnight's attorney to dismiss it, according to the Grand Junction Daily Sentinel. However, appellate judges John Dailey, Michael Berger and Jerry N. Jones ruled in favor of McKnight and his attorney and dropped the charges.
When Sergeant Folks deployed Kilo to sniff McKnight’s truck, Kilo displayed one of his trained indicators. Officers then told McKnight and the passenger to get out of the truck, searched it, and found a “glass pipe commonly used to smoke methamphetamine.”
In 2016, the Colorado Supreme Court ruled that marijuana odor could "contribute" to probable-cause determinations by police officers when they were trying to search a vehicle without a driver's permission. This ruling doesn't overturn that decision, but it does further clarify the phrase "contribute."
"Though Kilo’s alert did not alone give probable cause for the search of McKnight’s truck, it was of course indicative of possible criminal activity," wrote Dailey. "So the question remains whether the totality of the circumstances, including Kilo’s alert, established probable cause for the search.
"The result would be different if the dog was not trained to detect marijuana, or if the vehicle’s occupants were not at least twenty-one years old. And I do not opine as to whether the change in Colorado’s marijuana laws affects the Fourth Amendment analysis; like the majority, my analysis is limited to the Colorado Constitution," Dailey explained.