WASHINGTON (Reuters) – A senior U.S. Justice Department official who oversaw efforts to prosecute Islamic State sympathizers and pursue cyber criminals is leaving the Obama administration next month, he told Reuters on Tuesday. Assistant Attorney General John Carlin, chief of the national security division at the Justice Department, is departing on Oct. 15, less than a month before the U.S. presidential election. Carlin, 43, confirmed his departure, expected to be announced later on Tuesday, in an interview with Reuters.