Federal Police agents escort Jesus Enrique Aguilar, alias "El Mamito", to his presentation to the media in Mexico City, Monday July 4, 2011. Police believe Aguilar is connected with the killing of a U.S. Immigration and Customs Enforcement agent. According to authorities Aguilar is a former member of the Mexican Army and allegedly a co-founder of the Zetas drug cartel. (AP Photo/Alexandre Meneghini)