The US Justice Department has charged 28 members of Mexico's Sinaloa cartel, including three sons of drug lord Joaquin "El Chapo" Guzman, in a fentanyl-trafficking investigation. Known as the Chapitos, or little Chapos, the Guzman sons Ovidio Guzman Lopez, Jesus Alfredo Guzman Salazar and Ivan Archivaldo Guzman Salazar are "the more violent and aggressive faction of the cartel".