The leader of a shadowy group of assassins who work for the Gulf drug cartel was arrested Friday in northern Mexico after a gunfight with federal agents that left two suspects and one law-enforcement agent dead, the attorney general of Mexico announced Friday afternoon. The assassins’ suspected chief, Rogelio González Pizaña, is also wanted in the United States, where he is accused of threatening agents from the Drug Enforcement Agency at gunpoint in 1999.Full Story