A special panel of federal judges tentatively ruled Monday that California will have to release tens of thousands of inmates to relieve overcrowding over the next several years.
The judges said no other solution will improve conditions so poor that inmates die regularly of suicides or lack of proper care.
The state can cut the population of its 33 adult prisons through changes in parole and other policies without endangering the public, the judges said.
Reducing the prison population "could be achieved through reform measures that would not adversely affect public safety, and might well have a positive effect. This is particularly true considering that California's overcrowded prison system is itself, as the Governor as well as experts who have testified before the Court have recognized, a public safety hazard," the San Francisco-based panel said in a 10-page order.
The three judges did not set a final population figure, saying that will come later. They said they may hold more hearings before making the decision final.
In Monday's tentative ruling, the panel said they want the state to present a plan to trim the population of the nation's largest state prison system in two to three years.
"There are simply too many prisoners for the existing capacity," they wrote. "Evidence offered at trial was overwhelmingly to the effect that overcrowding is the primary cause of the unconstitutional conditions that have been found to exist in the California prisons."
The order came less than a week after the judges finished hearing two days of closing arguments. They said then that they wanted to quickly issue a tentative ruling in hopes of forcing the state to take steps on its own or reach a settlement with attorneys representing inmates.
In Monday's order, they offered the services of a court-appointed referee who could help with settlement talks. Previous negotiations failed, forcing the trial that took place over 14 days in November and December.