NEW YORK (AP) _ A man who ran onto the field at Yankee Stadium during the 1996 World Series with a taunt to Mayor Rudolph Giuliani written on his bare back was convicted Thursday of criminal trespass.

Judge Robert Torres ruled out efforts by the defense to show that Paul O'Grady was singled out for criminal prosecution because of politics. Torres limited testimony in the three-day trial in Bronx Criminal Court to whether O'Grady had run onto the field Oct. 26, 1996.

The shirtless O'Grady had cavorted onto the diamond during the sixth and final game against the Atlanta Braves. Scrawled on his back were the words, ``Mayor Giuliani, Kiss my...'', and an arrow pointing down.

His chest read, ``Howard Stern for Mayor.'' Defense lawyer Dino Lombardi had argued that O'Grady was selectively prosecuted because he was critical of the mayor. Another man arrested for running onto the field was charged with a violation, carrying no jail time.

The misdemeanor charge against O'Grady is punishable by up to 90 days in jail. No sentencing date was scheduled.

O'Grady, 24, now a resident of San Francisco, had no comment Thursday.

Lombardi said he would appeal the verdict.