PORTLAND, Ore. (AP) — Oregon’s first-in-the-nation experiment with drug decriminalization is coming to an end Sunday, when possessing small amounts of hard drugs will once again become a crime.

The Democratic-controlled Legislature passed the recriminalization law in March, overhauling a measure approved by 58% of voters in 2020 that made possessing illicit drugs like heroin punishable by a ticket and a maximum $100 fine. The measure directed hundreds of millions of dollars in cannabis tax revenue toward addiction services, but the money was slow to get out the door at a time when the fentanyl crisis was causing a spike in deadly overdoses and health officials — grappling with the COVID-19 pandemic — were struggling to stand up the new treatment system, state auditors found.

The new law taking effect Sunday, which passed with the support of Republican lawmakers who had long opposed decriminalization, makes so-called personal use possession a misdemeanor punishable by up to six months in jail. It aims to make it easier for police to crack down on drug use in public and introduced harsher penalties for selling drugs near places such as parks.

Supporters of decriminalization say treatment is more effective than jail in helping people overcome addiction and that the decadeslong approach of arresting people for possessing and using drugs hasn’t worked.

The new law establishes ways for treatment alternatives to criminal penalties. But it only encouraged, rather than mandated, counties to create programs that divert people from the criminal justice system and toward addiction and mental health services. Backers of the law say this allows counties to develop programs based on their resources, while opponents say it may create a confusing and inequitable patchwork of policy.

So far, 28 of the state’s 36 counties have applied for grants to fund deflection programs, according to the Oregon Criminal Justice Commission. The commission is set to disburse over $20 million in such grants roughly over the course of the next year.

Oregon House Republican Minority Leader Jeff Helfrich voted for the law but said he was concerned that counties didn’t have enough time to set up their programs.

“Unfortunately, I think we’re kind of setting people up for failure,” he said.

Multnomah County, the state’s most populous and home to Portland, plans to open a temporary center in October where police can drop off people who weren’t committing any other crime but drug possession. There, nurses and outreach workers will assess people and refer them for treatment. Until then, county mental health workers will respond to law enforcement in the field to help connect people with services, but people could still go to jail due to a variety of factors, including if those workers take longer than half an hour to respond, officials said.

“The criteria is very narrow to meet deflection: no other charges, no warrants, no violent behavior, medically stable,” said Portland Police Chief Bob Day.

In other counties, however, people with drugs who are also suspected of low-level public order offenses such as trespass will be eligible for deflection. Many counties plan to hold off on filing drug possession charges while people are completing programs.

The differences in deflection programs county to county are a concern, said Kellen Russoniello, the director of public health at the Drug Policy Alliance.

“It’s going to be this very complicated system, where essentially people who use drugs won’t know their rights and what to expect because it’s different in every single county,” he said. “Whether or not you are connected to services or you are just churned through the system will depend very heavily on where you happen to be in the state.”

He also said a potential influx of new drug cases could further strain Oregon’s legal system, which is already struggling with a critical public defender shortage, and that he thinks the focus should be on ramping up treatment capacity.

“We really need to focus on having the services available for folks if any of these deflection programs are going to be successful,” he said.

One of the law’s key drafters, Democratic state Rep. Jason Kropf, said each county has unique challenges and resources and that lawmakers will be monitoring “what’s working in different parts of the state.”

“I have optimism and I have hope,” he said. “I’m also realistic that we have a lot of work ahead of us.”

Over the past four years, Oregon lawmakers have invested more than $1.5 billion to expand treatment capacity, according to a recent report from the Oregon Health Authority. While that has funded over 350 new beds that are set to come online next year, the report found that the state still needs up to 3,700 beds to close gaps and meet future demand.