A 2014 California voter-approved initiative that reduced penalties for certain drug and property crimes has led to the lowest arrest rate in state history as police frequently ignore those illegal activities, experts say.

Proposition 47 lowered criminal sentences by reducing them from felonies that can bring long prison sentences to misdemeanors that instead bring up to a year in jail.

Recent state Department of Justice statistics show the number of felony arrests plummeted 28.5 percent last year, while misdemeanor arrests rose about 9 percent over 2014. That resulted in 52,000 fewer arrests overall and the lowest arrest rate since record-keeping began in 1960.

“It’s really driven by changes in drug and property arrests,” said Public Policy Institute of California researcher Magnus Lofstrom, who studies the issue. “I think it’s quite clear that Prop 47 is the major contributor to the changes we’ve seen.”

Last year’s decline in arrests, with the fewest felony arrests since 1969, is part of a long-term decline dating to the 1980s that has been spurred by the law as well as crowded jails and prisons and fewer police, Lofstrom said.

It’s too soon to say whether the changes are helping spur rising crime rates, though Lofstrom and other researchers are watching the relationship closely.

Law enforcement officials said drug offenders may now commonly be cited and released, or ignored because there may be little penalty if they are arrested. There were about 22,000 fewer drug arrests last year.

“The de facto decriminalization of drugs may have an impact,” said Kern County Sheriff Donny Youngblood, president of the California State Sheriffs’ Association. “We do know that there’s a lot less arrests being made, which means there are a lot more people on the streets using drugs.”

Multiple courts reported an increase in failures to appear for misdemeanor arraignments since Proposition 47 passed, the Judicial Council of California found in a survey of 40 of the state’s 58 county superior courts.

“If people aren’t showing up in court, if they’re not going to go to drug court, we’re going to see what we’re seeing, which is increased crime rates in our communities,” said Ventura Police Chief Ken Corney, president of the California Police Chiefs Association.

State Department of Justice figures show violent crime jumped 10 percent last year over 2014. Property crimes also increased, including a nearly 12 percent increase in shoplifting and nearly 11 percent increase in thefts, two crimes affected by Proposition 47.

But participation in drug courts has rebounded as counties adapted to Proposition 47 by including it in sentences for those charged with misdemeanors or drug-related crimes such as stealing to support their addictions, said Santa Clara County Judge Stephen Manley.

“I think it’s been a fairly dramatic response to getting treatment to the people that need it the most,” said Manley, president of the California Association of Drug Court Professionals.

Mel Sargent, 66, and Caroline Sargent, 54, even married on the day they graduated from an 11-month drug court program in March. Sacramento County probation officers bought them wedding rings.

“Before it was always the ‘war against drugs,’” Sargent said. “We got to see the other side, the more human side of the probation department and the judiciary.”

The initiative has also led to fewer plea bargains, probably because suspects have less incentive to accept plea deals without the threat of a felony conviction or prison time, the Judicial Council found.

It reported that prosecutors also seem to be filing more charges for felony drug sales, identity theft and robbery now that drug possession, writing bad checks and check forgery were reduced to misdemeanors.

“Some DAs’ offices have tried to charge their way around Prop 47, no question about it,” said John Abrahams, co-chairman of the California Public Defenders Association’s Legislative Committee.

But California District Attorneys Association Chief Executive Mark Zahner said law enforcement officials may now simply be targeting more serious criminals.

Lenore Anderson, who led the drive to pass Proposition 47, was pleased by reports that there may be an overall improvement in the justice system, even if the initiative is requiring some adjustment.

Law enforcement should accept that drug and property crimes still can bring appropriate punishment, while the changes leave more resources for serious felonies, said Anderson, president and executive director of the reform group Californians for Safety and Justice.

“My highest hope is that we start to really see some innovation that we haven’t seen in the past,” Anderson said.

For instance, this year’s state budget includes $15 million for police to experiment with using case managers and diversion programs to help prostitutes and low-level drug dealers instead of putting them in jail.

Without help, “they’re released in a short period of time and go right back to the same situation,” said Sen. Loni Hancock, a Berkeley Democrat, who pushed for the funding.