Mandatory state sentencing guidelines are the statutory maximum for purposes of applying the Apprendi rule. Decided June 24, 2004 (argued March 23, 2004). Opinion of the Court: Antonin Scalia → go there Dissenting: O'Connor, Kennedy, Breyer. Applied: the Sixth Amendment → go there Topic: Other criminal sentences. Blakely v. Washington, 542 U.S. 296 (2004), is a landmark decision by the Supreme Court of the United States in which the Court held, 5–4, that in the context of mandatory sentencing guidelines under state law, the Sixth Amendment right to a jury trial prohibited judges from enhancing criminal sentences based on facts other than those decided by the jury or admitted by the defendant. The landmark nature of the case was alluded to by Justice Sandra Day O'Connor, who characterized the decision as a "Number 10 earthquake". Wiki link