Does a positive alert by a well-trained and certified K9 constitute probable cause?

Yes, generally. See Florida v. Harris (2013) 568 U.S. 237. The Supreme Court held that the test to be applied is “whether all the facts surrounding a dog’s alert, viewed through the lens of common sense, would make a reasonably prudent person think that a search would reveal contraband or evidence of a crime. A sniff is up to snuff when it meets that test.” Harris, supra, at 248.

However, there have been new cases that hold, in the context of marijuana, the alert of a K9 is only part of determining probable cause. The Colorado Supreme Court, in People v. McKnight (2019) 2019 CO 36, has departed from United States Supreme Court precedent in holding that LE must have reasonable suspicion to believe that an item or area contains a drug in violation of state law before deploying a marijuana trained drug-detection dog for an exploratory sniff. Colorado goes on to hold that even if a marijuana trained K9 alerts, the alert is only a factor in determining probable cause. This is in direct conflict with the United States Supreme Court. Colorado justified the departure by stating that since a marijuana trained K9 could be detecting “legal” activity (personal possession of marijuana) this transforms the “sniff” into a search which needs probable cause to justify it.

California, until recently, has been in line with the United States Supreme Court; if evidence of marijuana comes to light, LE has the right to continue to investigate to determine if the marijuana is legally possessed. People v. Waxler (2014) 224 Cal.App.4th 712. However, in People v. Lee (4th Dist. 2019) 40 Cal.App.5th 853, the court held that since California law now “expressly provides that legal cannabis and related products “are not contraband” and their possession and/or use “shall [not] constitute the basis for detention, search, or arrest,” the small amount of marijuana found was not probable cause to allow for a search. While Lee was not a K9 case, it has ramifications for K9 sniffs. The courts could well follow Colorado’s lead. To address this, handlers should indicate that their K9 is trained in many scents and could be alerting to one or many scents. Also, be sure to note anything that would indicate illegal possession of marijuana; multiple phones, large amounts of cash, packaging, etc. or any other illegal possession of another controlled substance.

Other states are trending toward Colorado’s position as they legalize marijuana. Check with our member’s portion of the website for cases pertaining to your state.