In most of the country’s penitentiaries, National Guard troops remain outside while the authorities largely leave internal control of the facilities to groups of inmates, some of them heavily armed. In recent search of prisons, the authorities have reported finding assault rifles, submachine guns, handguns and grenades.
Prado said that National Guard soldiers are often to blame for allowing guns inside.
‘‘An important step has to be taken, and it’s taking the National Guard out of the prisons,’’ Prado said. ‘‘Who has the responsibility at the outside gate? It’s the National Guard.’’