A Sniff by a Pot-Detecting Dog Requires Probable Cause and Does Not Justify a Search, Says Colorado Supreme Court
Marijuana legalization changes the constitutional status of canine olfactory inspections.

Drug-sniffing dogs in states that have legalized marijuana should be worried about their job security in light of a decision that the Colorado Supreme Court issued yesterday. Confirming the 2017 judgment of a state appeals court, the justices said an alert by a dog trained to detect marijuana as well as other drugs no longer provides probable cause for a search in Colorado, where possessing an ounce or less of cannabis has been legal for adults 21 or older since 2012. Furthermore, the court ruled in Colorado v. McKnight, deploying such a dog itself counts as a search and therefore requires probable cause to believe a crime has been committed.
The case involved Kevin McKnight, who in 2015 was pulled over in Craig, Colorado, by Cpl. Bryan Gonzales, ostensibly for failing to signal a turn. Gonzales had been following McKnight because of behavior he deemed suspicious: He saw McKnight's pickup truck parked the wrong way in an alley near an apartment complex as a man stood by the passenger door. Although Gonzales "saw no behavior consistent with an exchange or transaction," he followed the truck to "a residence where police had found drugs almost two months earlier, and it remained parked there for approximately fifteen minutes," during which time no one left the house or the truck. When Gonzales stopped McKnight, he "recognized the passenger as someone who had used methamphetamine 'at some point in the past,' but he wasn't sure how recently."
Gonzales called Sgt. Courtland Folks of the Moffat County Sheriff's Office, who arrived with Kilo, a dog trained to bark when he smells marijuana, methamphetamine, cocaine, heroin, or MDMA. Kilo barked at the driver's door, prompting a search that discovered a pipe with methamphetamine residue in a storage compartment under the rear seat. After McKnight was convicted of possessing methamphetamine and drug paraphernalia, he appealed, arguing that Kilo's barking could not justify a search and that police needed more evidence to use the dog in the first place. The Colorado Supreme Court agreed on both points, overturning his convictions.
The U.S. Supreme Court, whose Fourth Amendment reasoning the Colorado Supreme Court has largely followed in applying the state constitution's ban on "unreasonable searches and seizures," has long maintained that an olfactory sweep by a drug-detecting dog does not count as a search because it reveals only the presence of contraband, a fact that people have no legitimate privacy interest in concealing. The Court has also held that such a dog's alert by itself is enough to justify a vehicle search, which requires probable cause but not a warrant (under the "automobile exception" to the warrant requirement).
As the Colorado Supreme Court observed, neither of those assumptions holds true any longer in Colorado. "Marijuana is not only decriminalized in Colorado, it is legalized, regulated, and taxed," the court said. Furthermore, Colorado's legalization initiative amended the state constitution to say that possessing an ounce or less of marijuana in public is "not unlawful and shall not be an offense under Colorado law." Hence cannabis consumers "have a state constitutional right not guaranteed by the federal constitution."
Since Kilo's barking could have indicated nothing more than a legal quantity of marijuana, the court said, it did not provide probable cause for a search, even when combined with Cpl. Gonzales' vague suspicions (and leaving aside all of the other reasons to question the accuracy of a police dog's purported response to car odors). Since Kilo's sniffing can reveal information about legal (but potentially sensitive) conduct, the court added, it qualifies as a search in itself.
"Because persons twenty-one or older may lawfully possess marijuana in small amounts, a drug-detection dog that alerts to even the slightest amount of
marijuana can no longer be said to detect 'only' contraband," the majority said. "An exploratory sniff of a car from a dog trained to alert to a substance that may be lawfully possessed violates a person's reasonable expectation of privacy in lawfully possessing that item. Because there was no way to know whether Kilo was alerting to lawful marijuana or unlawful contraband, Kilo's sniff violated McKnight's reasonable expectation of privacy. Therefore, under state law, Kilo's sniff was a search that had to be constitutionally justified."
Since it wasn't, the court reasoned, the sniff was illegal under Colorado's constitution. So was the ensuing car search, meaning that the evidence it discovered should not have been admitted and McKnight should not have been convicted. "We are the first court to opine on whether the sniff of a dog trained to detect marijuana in addition to other substances is a search under a state constitution in a state that has legalized marijuana," the justices noted, but "we probably won't be the last."
If Colorado police officers continue to deploy marijuana-detecting dogs, they will not be very helpful as an end run around privacy protections, since cops will need probable cause to justify the use of a tool that is supposed to provide probable cause but no longer does (except in conjunction with other evidence). In theory, a dog can be trained to stop alerting to marijuana, but it is not easy or cheap, and to be reliable a retrained dog requires periodic testing to show it continues to ignore pot. Alternatively, pot-sniffing dogs can be replaced by newly trained animals that are not taught to detect marijuana. Lest you think that the need for such expenditures means marijuana legalization is costing taxpayers money, note that drug dogs cost up to $10,000 each, or roughly what the government spends on a couple of pot busts.
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All that time and money put into training dogs to indicate for marijuana for easy busts gone to waste! Now they're going to have to claim that the dogs are trained to ignore marijuana when handlers tap on a vehicle when they want the pooch to react.
So glad to see states fighting to reclaim the fourth amendment.
HELP-HELP-HELP, won’t someone please give me some good advice?!!? I have a most EXCELLENT tax-money-saving idea that I’d like to put in to the Departments of Our Heroic Protectors in Government Almighty all across the land, and I just don’t know WHERE to submit my brilliant money-saving idea; PLEASE help. Idea summary: REAL drug-sniffing dogs are expensive to train, feed, house, and transport. EFFIGY dogs (think sock-puppet-doggie on officer’s hand) would be FAR less expensive! Officer waves sock-puppet-effigy-dog slowly over car, says wuff-wuff-wuff quietly and softly, then reaches trunk of car, goes WOOF-WOOF-WOOF loudly and urgently, now the car can be searched! Problem solved, cost-effectively! Woo-Hoo!!! … Now… HOW do we spread this most excellent idea? Please advise… This excellent idea brought to you by the Church of Scienfoology, see http://www.churchofsqrls.com/ …
EFFIGY dogs (think sock-puppet-doggie on officer’s hand)
So Triumph, the insult comic dog?
Well at least there's one good thing about moving to Colorado.
I missed the "automobile exception" in the Constitution.
Where was that again?
Our Constitutional rights have a lot of “exceptions,” that are only visible to judges and politicians. Though recently, the left has been able to find a whole bunch of previous unknown exceptions. Like “Hate Speech.”
It is inside the general welfare clause. That is where all fictional rights come from.
You mean fictional powers. Government does not have rights.
Since Kilo's barking could have indicated nothing more than a legal quantity of marijuana
I think it's clear the Supreme Court has a bias against anything named Kilo, even if it's spelled Kelo.
Nicely done.
AMENDMENT IV
The right of the people to be secure in their persons,
houses, papers, and effects, against unreasonable searches
and seizures, shall not be violated,
and no warrants shall issue, but upon probable cause,
supported by oath or affirmation, and particularly
describing the place to be searched, and the persons or things
to be seized.
In many jurisdictions a car on a public road is not a place where one can expect the same privacy as in a house. And different jurisdictions have different ideas how much privacy on can expect in the curtilige
In many jurisdictions, oddly enough mostly democrat controlled, a car on a public road is the only affordable place to live.
So house or car? Can that be like sex / gender, and left up to the opinion of the owner?
So police in those jurisdictions can just stop and frisk people.
My car is one of my effects.
Well this is an easy fix. All the current dogs can be put down anda whole new slew of inaccurate dogs can be 'trained' that detect everything the old ones did *except marijuana*
And we'll know its true because their training certificate says so.
Colorado needs more immigration.
I checked with mine and several other dogs I know.
They agreed on two points.
Squirrels bad.
Bacon good.
The legal implications I leave to experts in the field.
My dogs would like to amend the squirrels clause to include the mailman
Isn't this circular reasoning? The dog can detect multiple substances, several of which are still illegal in Colorado. Dogs can't talk, so the officer cannot possibly interpret a bark any other way than "something illegal is in there." Just because weed is legal now doesn't change the legality of the other substances, so unless the dog can be verfiably proven to detect only the illegal substances, I don't see how you can arrive at the conclusion they did.
"Since Kilo's barking could have indicated nothing more than a legal quantity of marijuana, the court said"
"who arrived with Kilo, a dog trained to bark when he smells marijuana, methamphetamine, cocaine, heroin, or MDMA. Kilo barked at the driver's door, prompting a search that discovered a pipe with methamphetamine residue in a storage compartment under the rear seat."
"the justices said an alert by a dog trained to detect marijuana as well as other drugs no longer provides probable cause for a search in Colorado"
Before someone reads this the wrong way, I'm not defending the search or use of dogs. I'm rather suspect of their accuracy as well. I just don't see sound logic in the court's reasoning here. If dogs can detect both legal and illegal substances and give the same signal for both, shouldn't the logical conclusion be not that this search was unwarranted, but that dogs cannot be used at all? The court says the dogs would have to be proven to not detect weed, but I don't know how you can possibly prove that when you can't prove it right now. And not just weed, but anything at all.
The court's reasoning only works if it is assumed that the dog will only alert on illegal substances. It's a step in the right direction, but I think you are right. It's not a reasonable assumption.
The use of dogs should be considered a search and require a warrant. I think that's the appropriate way to handle it. Establish probable cause sufficient to get a warrant. Then use the dog to help find what's listed on the warrant.
Gonzales called Sgt. Courtland Folks of the Moffat County Sheriff's Office, who arrived with Kilo, a dog trained to bark
Incidentally, the dog was also trained to bark when signaled by his handler to bark.
The dog is a police officer with a better sense of smell.
If you reek of alcohol or drugs or explosives that’s justification for a search.
The dog is a dog. A well trained working dog, but still a dog. I don't care if they put a badge on it, the dog is not a police officer. It can't talk, it can't swear an oath and it can't be held accountable for its actions.
... it can’t be held accountable for its actions.
I'm confused. I thought you were pointing out that the dog was not like a police officer.
Dogs can't
Police officers won't
I think you've got that last distinction backwards. A police dog may be more likely to get away with an unprovoked attack than a regular dog, but a vicious police dog is more likely to be destroyed than a vicious cop is likely to suffer any penalty more severe than a paid vacation.
[…] methamphetamine ‘at some point in the past,’ but he wasn’t sure how recently,” according to Reason. Gonzales called for a drug-sniffing dog named Kilo, who barked to indicate that he smelled drugs […]
[…] methamphetamine ‘at some point in the past,’ but he wasn’t sure how recently,” according to Reason. Gonzales called for a drug-sniffing dog named Kilo, who barked to indicate that he smelled drugs […]
Would be nice is we could train dogs to sniff our crooked politicians and dirty cops.
[…] Supreme Court makes landmark decision re: drug dogs due to legalization of […]