NEW : U.S. agency sends investigative team to help . The FBI is sending a new team of agents and investigators to the Middle East in an effort to find out what happened to three Americans who disappeared there last year. Vasconcelos was one of Mexico 's top experts on the fight against narcotraffickers and was said to have a price on his head . Mexico 's interior minister and two high-ranking officials among those killed . Interior minister is country 's second most-powerful post .
NEW : U.S. agency sends investigative team to help . The FBI is sending a new team of agents and investigators to the Middle East in an effort to find out what happened to three Americans who disappeared there last year. Mexico 's interior minister and two high-ranking officials among those killed . Interior minister is country 's second most-powerful post .