Reasons given for asking six U.S. attorneys to resign, according to William Moschella, an associate deputy attorney general. He testified Tuesday before the House Judiciary Committee. Carol Lam, the U.S. attorney in San Diego _VIOLENT CRIME: "Her gun prosecution numbers are at the bottom of the list." _IMMIGRATION: "Her numbers for a border district just didn't stack up." ___ John McKay, the U.S. attorney in Seattle _POLICY DIFFERENCES: "The department really had policy differences and were concerned with the manner in which he went about advocating the particular policies ... on information sharing. He spent quite a considerable amount of...