Hernandez acted as a warlord for Ernesto Fonseca Carrillo, Rafael Caro Quintero and Miguel Ángel Félix Gallardo. According to the DEA he is believed to have assisted in the transportation of two Americans, John Walker and Alberto Radelat, who were later killed by the cartel under the false suspicion they were DEA agents. Prior to his death he was wanted for questioning in the murder of DEA agent Enrique Camarena.[1][2]
Barba was killed on November 13, 1986[2] in a shoot-out with Mexican Federal Judicial Police in Mazatlán, Mexico. The DEA believes this may be part of a cover-up as the FJP has refused to turn over his fingerprints for identification.[1]