The Supreme Court (search) declined on Monday to consider whether hundreds of criminals who were sentenced prior to a landmark ruling on federal sentencing guidelines should receive reduced prison time.

Without comment, justices let stand a lower court ruling against Vladimir Rodriguez (search), a Florida man who challenged a nine-year drug sentence he received under mandatory guidelines that the Supreme Court subsequently threw out as unconstitutional.

The high court ruled Jan. 12 that the mandatory guidelines (search) violated a defendant's Sixth Amendment right to a jury trial. That's because the guidelines required judges to make factual decisions that affect prison time, such as the amount of drugs involved in a crime or amount of money involved in fraud.

Rulings generally do not apply to cases whose appeals were pending at the time of a decision unless there is "plain error." At issue was whether those criminal cases should presumptively be reviewed as wrong, or whether criminals must first provide strong evidence that the trial court would have imposed a lighter sentence.

The lower appeals courts are heavily divided on the issue, and both sides had urged the high court to hear the appeal. Some courts allow virtually automatic appeals, while others don't.

Rodriguez, who was convicted on a drug conspiracy charge, admitted to transporting 2,000 Ecstasy pills. But without a jury determination, the trial judge decided Rodriguez actually was responsible for 30,000 pills and increased his sentence from roughly 6 years to 9 years.

The case is Rodriguez v. U.S., 04-1148.