A Mexican national was executed Thursday for the rape-slaying of a teenager after the U.S. Supreme Court turned down a White House-supported appeal to spare him in a death penalty case where Texas justice triumphed over international treaty concerns. Humberto Leal, 38, received lethal injection for the 1994 murder of Adria Sauceda. She was fatally bludgeoned with a piece of asphalt. Leal was pronounced dead at 6:21 p.m. EDT (2221 GMT).