California will begin to reduce its prison population by about 6,500 inmates over the next year under a state law that takes effect Monday.

The bill was signed as part of last year's state budget package. Under it, early release credits for inmates who complete educational and vocational programs will be expanded, letting more inmates leave prison earlier.

At the same time, the state will stop its monitoring of low-level offenders after their release. That is designed to reduce the number of parolees returned to prison, essentially because the state will not know if they are violating the terms of their parole.

Corrections Secretary Matthew Cate told The Associated Press on Thursday that the law will let parole agents concentrate on more dangerous ex-convicts.

Agents will be responsible for supervising an average of 48 parolees instead of the current 70 because the law ends California's practice of automatically putting every released convict on three years of parole.

Ex-convicts deemed less dangerous or less likely to commit new crimes will not be monitored at all, although they still can be searched without a warrant.

The reduced caseload will let the state more intensively watch gang members, sex offenders and violent felons, using lessons it learned from its failure to catch Jaycee Dugard's accused kidnappers, Cate said. Parole agents have been faulted for failing to learn that paroled sex offender Phillip Garrido was hiding the young woman in his backyard for nearly 20 years.

"We're going back to the time when the parole officer not only has time to be a cop, but add that social worker factor," Cate said in a telephone interview. "We could see the recidivism rate actually go down in California, so that's the great hope."

Groups representing crime victims and the union representing Los Angeles police officers criticized the new law.

"California has decided to begin jeopardizing public safety with no perceivable financial benefit," said Los Angeles Police Protective League President Paul M. Weber in a statement.

He argued that despite the short-term financial gain, an increase in crime will cost the state and victims more in the long run.

Cate acknowledged some unsupervised ex-felons will inevitably commit serious crimes after their release. But he said residents will be safer in general because parole agents will be able to concentrate on higher-risk parolees.

Gov. Arnold Schwarzenegger signed the law in October. Finance officials estimated Thursday the measure will save the state about $500 million its first full year.