 By Luc Cohen NEW YORK Reuters - Opening statements are set to begin on Monday in the U.S. trial of a former Mexican law enforcement official once in charge of cracking down on drug trafficking, who now stands accused of taking bribes from the powerful Sinaloa Cartel. Genaro Garcia Luna led Mexicos Federal Investigation Agency from 2001 to 2005 and was Public Security Minister from 2006 to 2012, during which time he worked closely with U.S. counter-narcotics and intelligence agencies. He plead... 