U.S. and Mexican law enforcement confirm that two of four U.S. citizens abducted in Matamoros, Tamaulipas, were killed by a Gulf Cartel cell. Breitbart Texas has confirmed through local authorities the identity of the crime boss responsible for the case. The fates of the other two Americans remain unclear. Breitbart Texas confirmed that both the FBI and Homeland Security Investigations are working with Mexican authorities to locate the missing individuals.