PHOTO Robert Couse-Baker

Cops used to flip low-level “offenders” busted with cannabis to become snitches. Now, with weed legal, they can’t!

As promised, marijuana legalization has profoundly changed American policing, but not in the way legalization advocates predicted.

Yes, marijuana arrests have declined in some jurisdictions. According to cops, that’s the problem: Rather than allowing police officers to focus on more serious crimes, legal cannabis has made police work more difficult. As law-enforcement officers recently told researchers at Washington State University, without low-level marijuana crimes on the books, police are having difficulty cultivating informants. According to the study, informants were people who, picked up on a low-level cannabis bust, would have previously been flipped into a source to avoid punishment.

Though relying too heavily on informants leads to both over policing as well as deadly raids on innocent people — as well as serious consequences for the informant, whose personal security is at risk after being branded a “snitch” — without informants at all, more serious cases can’t be cracked.

According to the Spokesman Review, WSU researchers interviewed some 150 cops around Washington state, which, along with Colorado, was the first in the United States to legalize cannabis in 2012. Sales began in 2014.

For the most part, cops’ woes in Washington resemble complaints registered elsewhere. A common thread is that dogs serving in canine units, trained to sniff out cannabis, have had to be retrained, retired, or transferred to careers detecting marijuana in schools (one area where “legal” cannabis is still a criminal offense). Another is that despite statistics stating otherwise, police adamantly believe that marijuana legalization has somehow led to an increase in crime, particularly around cannabis retail outlets.

Drug-dog alerts are unreliable. According to findings accepted by the U.S. Supreme Court, almost all U.S. currency has traces of drugs on it, so a canine can alert to any amount of money; further, a canine unit can also be trained by its handler to “alert” to anything at all.

But perhaps drug dogs are not as unreliable as people. Police have to had to hire new dogs trained to sniff other drugs, but they’ve also had to figure out how to get new human sources and that’s proven far more difficult.

In interviews with researchers, police “said, ‘Marijuana was how we got CIs [confidential informants],’” said David Makin, a researcher at WSU’s Criminal Justice Department, in comments to the Spokesman-Review.

Cops complained about legalization in other predictable ways. One county sheriff actually went on record to say that the data that shows dispensaries have either had a negligible effect or caused crime to go down shouldn’t be trusted, because well, apparently data — the bedrock upon which “science” is built — can’t be trusted.

“It’s one thing to look at pure statistics and numbers,” Spokane County Sheriff Ozzie Knezovich told the newspaper. “It’s another thing to come down and talk to people about life on the street.”

Though legalization means police have to adjust and they may not be too happy about it, a shift away from confidential informants and towards other, more reliable evidence might both increase trust in police. It could also save lives, by preventing no-knock raids on innocent people like the Houston couple greeted by armed men in kevlar at their door.

As the ACLU recounted, Dennis Tuttle and Rhogena Nicholas, a married couple in their 50s, were at home when police burst into their home in a no-knock raid. They were there because a confidential informant had told them, mistakenly, that the couple were dealing heroin.

The couple’s dog charged at police, who opened fire and killed the dog. Tuttle, a Navy veteran and — like many Texans — a gun owner, came at the police firing his own weapon. Both he and Nicholas were killed.

Marijuana is not legal in Texas, and legalization might not have convinced cops’ bad source to not give them bad information and it might not have prevented police from using that bad information. And in serious cases involving, say, terrorism or organized crime, flipping a low-level operative to snitch on the big boss could save many, many lives. But how likely is it an al-Qaeda cell or a mafioso honcho is going to be the prize won after cops bust smoking weed? You’ll have to ask them, and they may tell you to ignore the data and trust them… because that’s always worked.

TELL US, would you ever work with the police?