UNITED STATES.- California voters’ decision to reduce penalties for drug and property crimes in 2014 contributed to a jump in car burglaries, shoplifting and other theft, researchers reported.

Larcenies increased about 9 percent by 2016, or about 135 more thefts per 100,000 residents than if tougher penalties had remained, according to results of a study by the nonpartisan Public Policy Institute of California released Tuesday.

Thefts from motor vehicles accounted for about three-quarters of the increase. San Francisco alone recorded more than 30,000 auto burglaries last year, which authorities largely blamed on gangs. Shoplifting may be leveling off, researchers found, but there is no sign of a decline in thefts from vehicles.

Proposition 47 lowered criminal sentences for drug possession, theft, shoplifting, identity theft receiving stolen property, writing bad checks and check forgery from felonies that can bring prison terms to misdemeanors that often bring minimal jail sentences.

While researchers can link the measure to more theft, they found it did not lead to the state’s increase in violent crime.

Violent crime spiked by about 13 percent after Proposition 47 passed, but researchers said the trend started earlier and was mainly because of unrelated changes in crime reporting by the FBI and the Los Angeles Police Department.

The FBI broadened its definition of sexual crimes in 2014, while the LAPD improved its crime reporting after previously underreporting violent crimes. If it weren’t for those changes, researchers found California’s violent crime rate would have increased 4.7 per- cent from 2014 to 2016.

Researchers compared California’s crime trends to those in other states with historically similar trends. They found the increase in California’s violent crime rate was less than that of comparison states, but larcenies jumped in California as they declined elsewhere.

California still has historically low crime rates despite recent changes in the criminal justice system aimed at reducing mass incarceration and increasing rehabilitation and treatment programs, said Lenore Anderson, executive director of Californians for Safety and Justice, who led the drive to pass Proposition 47.