A baseball fan who jumped from the upper deck at Yankee Stadium onto the netting behind home plate has been banned for life from the ballpark and could be sent to jail, a judge said Wednesday. Scott Harper, 19, of Armonk, N.Y., pleaded guilty Wednesday to reckless endangerment following last season's plunge at the Yankees' Bronx stadium. District Attorney Robert Johnson recommended probation and restitution to the Yankees, but Harper rejected the deal. Harper's criminal sentence, to be handed down September 19, will depend on the outcome of another case in Westchester County for driving under the influence of alcohol or drugs, state Supreme Court Judge Troy Webber said.