In a novel experiment, the Chicago Police Department has rounded up dozens of drug addicts over the past two years and has given them an ultimatum: treatment or jail.

Most opted for treatment and only a handful were rearrested.

Now, the department plans to expand that pilot program.

Starting next year, patrol officers will identify candidates for diversion and bring them to a West Side police station where treatment experts will evaluate them for entry into the appropriate therapy. The goal is to expand the program citywide.

Until now, the department’s narcotics division has coordinated the experiment. The patrol bureau will take over the expanded program.

“I have often said that we can’t arrest our way to a safer Chicago,” police Supt. Eddie Johnson said in a statement. “While it’s important for us to focus on the individuals driving the violence on our streets and hold them accountable for their actions, we must appropriately address non-violent drug offenders before they commit additional crimes.”

This syringe was left on the ground in a West Side alley. | Frank Main/Sun-Times

“Through our diversion pilot program, these individuals receive the treatment they need in a proper facility and not in a jail cell, Johnson said. “This approach has led to significantly reduced recidivism rates for those in the pilot and has shown us the path forward as we look to expand this effort.”

The University of Chicago Health Lab studied the original pilot program, which began in early 2016. It was designed to help stem the hundreds of deaths related to heroin and fentanyl overdoses on the West Side every year.

According to one report by Roosevelt University, more than 18,000 people were hospitalized for heroin overdoses in 2010 on the West Side, where street-corner dealers stay busy serving suburban and local customers alike in neighborhoods along the I-290 Eisenhower Expressway, sometimes called the “heroin highway.”

In the pilot program, narcotics officers picked up 41 people for trying to buy drugs, usually “dime bags” of heroin for $10. Forty of them agreed to undergo treatment. Of them, two were rearrested, one for having a suspended license and the other for drug possession.

Narcotics officers also rounded up 46 people caught trying to sell drugs to officers. Of that group, 40 took the treatment option. Slightly more than half of them have been rearrested, almost exclusively for drug-related offenses and other misdemeanor crimes, according to Amy Cadwallader, research manager for the U of C Health Lab.

Harold Pollack | File photo

The researchers were interested to learn that while drug buyers had a far lower rearrest rate than drug dealers, the dealers seemed to have embraced treatment more than buyers did.

Only 38 percent of the buyers actually entered treatment — even though they had agreed to do so —  compared with 68 percent of the dealers. And 56 percent of the dealers stuck with their treatment for a month or more, compared with 30 percent of the buyers.

Harold Pollack, a University of Chicago professor who evaluated the program, said the police did a good job of selecting candidates who didn’t have violent histories. None of the new arrests were for offenses involving violence or death, he noted.

“The police demonstrated that these people could be safely diverted,” Pollack said, adding that the program saved the city and county money that would have been spent on prosecuting and housing the addicts in the criminal-justice system.

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Pollack said he expects about two people a day will get diverted from jail in the program that starts on the West Side next year.

“It’s not going to be a massive thing, but a helpful thing,” he said.