On Monday, the Colorado Supreme Court attacked the role of police dogs trained to detect marijuana. And it’s created yet another break between how state and federal law enforcement can investigate pot.

The ruling was 4-3. In it, the court said that, under the state constitution, a dog trained to alert to marijuana cannot be used before an officer establishes probable cause that a crime had been committed.

That changes decades of procedure where police dogs were trained to alert their handlers to the presence of pot.

But that sniff test has been up for debate since Coloradans voted in 2012 to legalize recreational possession of small amounts of the drug.  Why?  Because they can alert even if a person has a legal amount of marijuana.

According to Sam Kamin, a law professor at the University of Denver who studies marijuana law and policy, the ruling effectively renders the dogs trained to detect pot useless in most situations.

Prior to the ruling, the dogs’ sniff tests were used to create probable cause for a search.

But now there needs to be enough evidence to authorize a search before a marijuana-trained dog can be used, and that makes the dogs’ sniff tests redundant.

“The dog’s sniff arguably intrudes on a person’s reasonable expectation of privacy in lawful activity,” Supreme Court Justice William Hood wrote in the majority’s decision. “If so, that intrusion must be justified by some degree of particularized suspicion of criminal activity.”

The ruling means that officers using such K-9s are now subject to the same standards used for other searches of property.

The way it breaks down is that police using pot-trained dogs either have to have a warrant before the sniff test or be in one of a handful of situations outlined by state law that allows police to complete a search without a warrant.

The ruling doesn’t come as a surprise to many Colorado departments that had begun retiring or phasing out weed-trained dogs in favor of K-9’s not trained to detect the drug.

There are about 120 police dogs in Colorado, and less than 20 percent are still trained to detect marijuana.

The Colorado Attorney General’s Office said they’re still reviewing the.

“We will work with our law enforcement partners in understanding this decision’s possible implications,” Attorney General Phil Weiser said in a statement.

According to David Ferland, executive director of the United States Police Canine Association, the decision isn’t out of line with how other state courts treat drug-dog sniff tests.

“What Colorado is doing does not surprise me,” Ferland said. “That’s not going to be earth-shattering.”

He did, however, argue that there would have been significant repercussions if the court ruled that all tests conducted by marijuana-trained dogs were unconstitutional.

According to Kamin, the decision does not apply to federal law enforcement agencies working in Colorado, like the Drug Enforcement Administration.

It specifically states the justices considered the issues only as they apply to the state constitution, which means the ruling cannot be appealed to the federal courts.

Three of the court’s seven judges disagreed with the majority’s findings. 

Why? 

Because they questioned how the decision meshed with the U.S. Constitution and federal law, which still prohibits marijuana in any amount.

It’s yet another example of the complications created by the conflict between state and federal marijuana laws.

That’s according to Chief Justice Nathan Coats in his dissent, which called the majority’s opinion “deeply flawed.”  He argues the ruling creates a system in which a sniff test by a marijuana-trained dog is a search under the state constitution, but not under the federal constitution.

Hood, who is the justice who wrote the majority opinion, said the court had to consider Colorado’s specific laws – not federal law.

“To the extent we end up alone on a jurisprudential island, it is an island on which Colorado voters have deposited us,” he wrote. “Our role is not to question their decision. Rather, it is to apply the logic of existing law to a changing world. Though 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, we probably won’t be the last.”

Kamin said it’s not uncommon for states to have rules about evidence that differ from federal standards, even outside of marijuana cases.

“I just don’t see the conflict (the dissenting justices) are so worried about,” he said.

The case came up because of a 2015 incident in Moffat County during which a Craig police officer stopped a suspicious truck.

During that stop, the officer then requested that a K-9 conduct a sniff test of the truck… and the dog, Kilo, alerted that drugs were inside.

Deputies then searched the truck and found a meth pipe with some residue and arrested the driver, Kevin McKnight.  He was later convicted of two drug-possession charges.

But that dog Kilo was trained to alert to marijuana as well as cocaine, heroin, ecstasy and methamphetamine… because police dogs are not trained to give different signals for different drugs.

In the appeal, McKnight’s attorneys argued that the deputies’ search was illegal because Kilo could have been alerting to the presence of a legal amount of marijuana. They said the officers didn’t have enough evidence to search the truck otherwise.

The Colorado Supreme Court agreed and sided with the convict, comparing the sniff to technologies such as thermal-imaging devices that could show both private, legal activity along with illegal acts.

In their ruling, the court reversed McKnight’s convictions – despite his possession of the drugs.

“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,” the court’s majority opinion states.