A sweeping bill to reform Nevada’s criminal justice system and reduce penalties for some crimes has passed its first committee, but not without some significant changes.

The Assembly Judiciary Committee voted 10-5 on Tuesday on AB236, a bill based on 25 recommendations from the state’s Advisory Commission on the Administration of Justice after the Crime and Justice Institute combed through reams of data about what’s driving the state’s rising prison population. The institute said implementing the full slate of recommendations could save some $640 million in prison costs over 10 years.

All Republicans opposed the bill, with several saying they appreciated all the work that went into the measure but weren’t ready to support it.

After two months of negotiations on the bill, lawmakers produced a major amendment and scheduled a vote last week. But that vote was postponed for further work.

The most significant change finalized Tuesday deals with the crime of drug possession. The bill originally sought to reduce possession — when there is no evidence the person intended to sell drugs — to a misdemeanor, on the basis that a drug user should be treated for addiction rather than heavily prosecuted.

But the bill has now restored that to a low-level Category E felony, with a defendant being sent to mandatory diversion programs on the first two offenses.

Democratic Assembly Judiciary Chairman Steve Yeager said the change had to do with concerns about the ability of labs to test drug evidence. A felony drug possession case starts in justice court with a preliminary hearing, at which a police officer’s field test for drugs can suffice as evidence for the case to proceed to the district court. A lab test of the drug evidence is required at trial.

A misdemeanor case would not include a preliminary hearing and would immediately need a lab test. Trouble getting those done in a timely fashion could lead to the case being dismissed.

“The last thing I want is for that to sort of be the word on the street, right? ‘Well if you just get a misdemeanor and set it for trial, they won't be ready. In that case, it’ll have to be dismissed.’ That's not a good situation,” Yeager said in an interview on Monday.

Yeager said he “wasn’t really thrilled” to have to upgrade drug possession to a felony because he believes it contradicts the science of substance use disorders.

“I think this was the right move to make at this point, but I'm still hopeful that ... this conversation doesn't end here,” he said, “and two, four, six years down the road, we're figuring out really how to set up a system where minor drug possession is treated the way that it should be treated, which really is a behavioral health issue more than a criminal issue.”

With less than three weeks left to go in the session, the bill still needs to pass the full Assembly, a Senate committee and the full Senate.