The Plata v. Brown case involves constitutional violations in California's prison system, specifically violations of the Cruel and Unusual Punishments Clause guaranteed by the Due Process Clause of the Fourteenth Amendment. The Supreme Court affirmed the three-judge court's order to limit the population in California's overcrowded prisons, which violates prisoners' constitutional rights. The court ordered California to reduce its prison population to 137.5% of the prisons' design capacity within two years, requiring a population reduction of 38,000 to 46,000 persons. The PLRA restricts the circumstances in which a court may enter an order that reduces or limits the prison population, but the order in this case can be achieved by increasing prison capacity or transferring prisoners to other facilities. The three-judge court must determine by clear and convincing evidence that overcrowding is the primary cause of the violation of a federal right and that no other relief will remedy the violation. The relief granted must be narrowly drawn and extend no further than necessary to correct the violation of the federal right of a particular plaintiff or plaintiffs. The State argues that it was an error to convene the three-judge court without giving it more time to comply with prior orders in Coleman and Plata. The Supreme Court has the authority to review the decision to convene a three-judge court, despite the argument that the State should have appealed the orders of the District Courts in the Court of Appeals first.

The court's decision to release 46,000 convicted criminals is criticized for violating the Prison Litigation Reform Act of 1995. Structural injunctions that involve judges in policymaking outside of their legal role are also opposed. Judges are urged to exercise restraint in cases involving state penal systems and defer to appropriate prison authorities. The PLRA mandates that relief be narrow and limited to correct the violation of Federal rights in the least intrusive way possible. Structural injunctions, particularly prisoner-release orders, are seen as raising separation-of-powers concerns and exceeding the historical role and institutional capability of courts. In this case, the District Court's order to release 46,000 prisoners in California is deemed to extend further than necessary to correct the violation of the federal right of a particular plaintiff or plaintiffs and is therefore forbidden by the PLRA and defies the proper role of judges.

The dissenting opinion argues that the three-judge court exceeded its authority under the Prison Litigation Reform Act of 1995 by ordering the release of 46,000 inmates without adequately establishing a violation of the Constitution and without considering evidence of present conditions in California prisons. The relief must be narrowly tailored to correct the violation of a federal right and be the least intrusive means necessary. The majority of the Supreme Court relied on outdated statistics and anecdotal evidence when assessing the current state of the California prison system. The California prison health care system has multiple issues, but improvements can be made without compromising public safety, such as targeted reductions in the State's prison population and transferring prisoners to out-of-state facilities. The three-judge court's conclusion that releasing 46,000 criminals would improve public safety is debatable, and the State had informed the court that reducing the prison population to 137.5% within a two-year period would compromise public safety.