In a unanimous opinion, the high court refused to reverse the conviction of Michael Rivera, who was found guilty of first degree murder in the shooting death of 16-year-old Marcus Lee and sentenced to 85 years in prison.

Rivera's lawyer wanted to use one of his peremptory challenges on a female juror candidate, but a state judge refused to let him do it. The woman, Deloris Gomez, a business office supervisor at Cook County Hospital's outpatient orthopedic clinic, went on to become the jury forewoman.

The Illinois Supreme Court said she should have been dismissed, but that the error was harmless. Rivera's lawyers argued that the seating of an illegal juror should have required an automatic reversal.

"A state trial court's good faith but erroneous denial of a criminal defendant's peremptory challenge, we hold, does not require automatic reversal of the defendant's conviction, provided that all persons seated on the jury are qualified and unbiased," said Justice Ruth Bader Ginsburg, writing for the court.