Saying that jamming more than 150,000 inmates into facilities designed for just over half that number has resulted in health care so poor it amounts to cruel and unusual punishment, a panel of three federal judges Aug. 4 ordered California to slash its prison population by more than a quarter over a two-year period.

The decision confirms the panel’s preliminary ruling in February that the intense crowding, which has prisoners sleeping in triple-deck beds in gymnasiums, halls and day rooms and often puts one guard in charge of monitoring large numbers of inmates, is the main cause of the abysmal health care situation. The judges said that in the last four years, an inmate has died needlessly an average of once a week.

The panel pointed out that California officials had not fulfilled previous orders to fix the overcrowding and the health care system. They ordered the state to develop a detailed plan within 45 days, to cut the population in the state’s 33 adult prisons to 110,000 within two years. This would still leave the prisons at 137.5 percent of designed capacity.

The judges maintained the cuts could be made “without a meaningful adverse impact on public safety” and without releasing inmates “indiscriminately” by assigning minor parole violators to local treatment, electronic monitoring or work-furlough programs instead of returning them to prison. They also suggested trimming sentences of low or moderate risk prisoners who participate in work, education or rehabilitation programs.

“In these overcrowded conditions, inmate-on-inmate violence is almost impossible to prevent, infectious diseases spread more easily, and lockdowns are sometimes the only means by which to maintain control,” the panel said in its 184-page order.

“The medical and mental health care available to inmates in the California prison system is woefully and constitutionally inadequate, and has been for more than a decade,” the order said.

Republican Governor Arnold Schwarzenegger’s administration, and Republican legislators, quickly said they each would file appeals to the U.S. Supreme Court. But prison reform advocates welcomed the ruling.

“We think it is a historic decision that should shift the tide in California corrections in a more sensible direction,” Rebekah Evenson, a staff attorney with the Berkeley-based Prison Law Office, said in a telephone interview. She said the state’s “unsustainable” expansion of its prison population over decades, and the resulting inability to provide inmates with “even the most basic health and mental health care“ were issues the Prison Law Office had raised in the lawsuit that led to the panel’s ruling.

Evenson said those who claim such an inmate release would endanger public safety are “absolutely wrong about that.” She said California imprisons “huge numbers” of parolees for technical violations and has a number of other policies and practices that are “completely out of step with the rest of the country.”

The issue of prison overcrowding figured prominently in just-concluded negotiations to bridge a $26 billion gap in the state’s general fund. Gov. Schwarzenegger’s proposal to cut the prison population by 27,000 and at the same time cut prison spending by $1.2 billion was rejected by Republican legislators. The legislature will resume discussion later this month on how to cut the prison budget.

Senate President Pro Tem Darrell Steinberg, D-Sacramento, said of the panel’s ruling, “The case for reform cannot be any clearer. We will return in August to produce reform that saves money, protects public safety, and takes back the control of our prison system.”

But Sen. John Benoit, R-Palm Desert, vice chair of the Senate’s Public Safety Committee, called the release of inmates “a horrible way to accomplish anything except higher crime rates.”

The three judges on the panel were Stephen Reinhardt of the U.S. Court of Appeals for the Ninth Circuit and Federal District Court judges from California, Lawrence K. Karlton and Thelton Henderson. Three years ago Judge Henderson appointed a receiver to manage the state’s prison health care after finding inadequate health care was causing an average of one inmate death per week.