California was supposed to reduce the population in its 33 adult prisons to about 110,000 inmates by June, but Brown says he can't comply without releasing dangerous criminals, in violation of state law.
Instead, he is asking a three-judge panel to lift the inmate population cap, which was imposed as a way to improve the medical and mental care of inmates. The governor says California's prison system has improved its health care operation so much that it can provide care even with nearly 10,000 more inmates than allowed by the court.
In Tuesday's order, the judges said California is obligated to keep trying to meet the cap as the legal fight continues. But they extended the deadline to Dec. 30.
The judges set the cap in 2009, and it was supported by the U.S. Supreme Court in 2011. However, Brown said he is prepared to appeal again to the nation's high court on the grounds that conditions have greatly improved since the first order.
The state had asked for the six-month deadline extension and welcomed the delay, said Jeffrey Callison, a spokesman for the California Department of Corrections and Rehabilitation.
Inmate rights attorney Don Specter, who is suing the state over prison crowding, said California
"The court is bending over backwards to accommodate the state's interest in public safety," said Specter, director of the Prison Law Office. "We expect them to obey the court's order to take all the steps necessary to meet that deadline."
In a separate but related filing, one of the three federal judges set a March 27 hearing for arguments over whether he should end a long-running lawsuit over inmate mental health care.
U.S. District Judge Lawrence Karlton of Sacramento has until April to rule on Brown's demand that the court end his oversight of the treatment of mentally ill inmates.
A court-appointed special master recently said it is too soon to end federal monitoring, given the state's relatively high rate of inmate suicides and continued delays in providing treatment.
Brown's administration filed a strongly worded response Tuesday, arguing that the suicide rate is misleading and that the prison system has taken proper steps to aid mentally ill inmates.