In Brown v. Plata , the United States Supreme Court, Case # 09-1233, [5/23/2011 , DAR #: 7326]
decided the Ninth Circuit decision to order California to reduce its inmate population as valid.
A federal three-judge panel ruling to reduce the state prison population to 137% of capacity is upheld. The medical and mental health care provided in California's prisons falls below the standard of decency inherent in the Eighth Amendment. The extensive and ongoing constitutional violation cannot be remedied without a reduction in overcrowding. The state is ordered to implement the order without further delay. See the opinion See the court opinion here.
Side Note: I am by far a statistician, however believe the eventual over population of the prison system due in part to Three Strikes was clear. Simply put, you cannot require prison terms are served if you don't build new prisons due to the expected increase in inmate population. The end result is releasing offenders to make room for new inmates who may not be as worthy to be in prison as the ones they are making room for. See, initial Three Strikers get life for minor thefts and pizza slice.