The Supreme Court on Monday struck down California's sentencing law because it gives judges too much power to increase sentences based on facts not found by the jury.

The 6-3 ruling in California v. Cunningham may throw into uncertainty a segment of recent sentences imposed in California under the state's 1977 sentencing law.

"California has some work to do, but it should not cause havoc in the courts," says Stanford Law School professor Jeffrey Fisher, who wrote a brief in the case for the National Association of Criminal Defense Lawyers and is a key strategist in challenges to sentencing laws. Fisher said defendants on direct review should get a "fresh look" at their sentences as a result of the ruling Monday.

The decision also signals that the newly constituted Roberts Court is committed to the Apprendi line of cases, which, since 2000, have recalibrated the balance between judges and juries in the sentencing process and upended both state and federal sentencing laws. In Apprendi v. New Jersey, the Court held that any fact that increases a sentence beyond certain parameters set forth in the sentencing statute must be determined by a jury beyond a reasonable doubt.

"Because the [California law] authorizes the judge, not the jury, to find the facts permitting an upper-term sentence, the system cannot withstand measurement against our Sixth Amendment precedents," Justice Ruth Bader Ginsburg wrote for the majority.

Chief Justice John Roberts Jr. voted with the majority upholding the Apprendi precedents, whereas his predecessor William Rehnquist opposed the recent sentencing decisions. Justice Samuel Alito Jr. dissented Monday, as his predecessor Sandra Day O'Connor probably would have. Justice Anthony Kennedy, joined by Justice Stephen Breyer, also dissented, asserting, "In my view, the Apprendi line of cases remains incorrect."