SACRAMENTO, Calif. (AP) — Gov. Jerry Brown is challenging a federal court order that California further reduce its inmate population to improve prison conditions, reigniting a legal battle that already once reached the U.S. Supreme Court.

Complying with the court's June deadline for lowering the prison population would endanger public safety, Brown contends in court filings seeking to overturn the deadline and the court's population cap.

"The overcrowding and health care conditions cited by this Court to support its population reduction order are now a distant memory," the administration argued in its court filings overnight Monday. "California's vastly improved prison health care system now provides inmates with superior care that far exceeds the minimum requirements of the Constitution."

The cap was imposed in 2009 after federal judges blamed crowding for causing conditions so dismal that they violated inmates' constitutional rights and resulted in the death of an average of one inmate each week due to neglect or poor care. The judges gave the state until June to reduce the population of California's 33 adult prisons by about 33,000 inmates, to a total of 110,000 inmates.

The decision was upheld by the U.S. Supreme Court in 2011, and so far the federal judges have said they will not consider raising the cap.

That didn't deter the state from making the attempt.

"Any further federally ordered reduction of the California prison population is unnecessary and a threat to public safety," Jeffrey Beard, the new secretary of the Department of Corrections and Rehabilitation, said in a statement provided to The Associated Press.

Beard noted that the state has reduced its prison population by about 43,000 inmates since 2006 while improving its treatment of mentally and physically ill inmates. State officials say California's less serious offenders already are going to county jails under a 14-month old law that sends only serious, violent and sexual offenders to state prisons. That makes it more difficult to identify remaining criminals who could be safely released.

"Instead of ordering the early release of potentially thousands of serious and violent felons, it is hoped that the federal court will recognize that we are now providing a constitutional level of care, and therefore an arbitrary population cap is unwarranted," said Beard, who became secretary last month after previously heading Pennsylvania's prison system.

Brown planned news conferences in Sacramento and Los Angeles on Tuesday to publicly make the state's argument.

His reasoning drew swift criticism from reformers who said the state could do more to divert inmates from prison.

"Rather than implement the kinds of sentencing reforms that would significantly reduce the number of people needlessly behind bars in California, Gov. Brown has instead committed to business as usual," said Allen Hopper, director of criminal justice and drug policy for the American Civil Liberties Union of California. Spending more money on prisons means less money for other needs like public schools, he said in an email.

Attorneys representing inmates argued in their own court filing that the state is still failing to provide proper care and could release more prisoners without endangering the public. Though conditions have improved, inmates still are needlessly dying of neglect and mentally ill inmates go untreated, they contend.

Michael Bien, one of the lead attorneys for inmates, said it would be cheaper and more effective to funnel many criminals into drug or mental health treatment programs than into prison. Moreover, more inmates already behind bars could be safely released after completing drug, vocational, educational or other rehabilitation programs that would reduce their likelihood of committing new crimes, he said.

Copyright 2013 The Associated Press.