The U.S. sent 238 Venezuelan migrants to a Salvadoran mega-prison. The Trump administration says they're all gang members, but 60 Minutes could find no criminal records for 75 percent of them.

As it stands, Kilmar Abrego Garcia's story begins and ends in his native El Salvador. When he was a boy, a local gang extorted his family, tried to indoctrinate him and threatened to kill him, according to his immigration case.