The Venezuelans emerging from their plane were not in prison clothes, but in designer jeans and branded tracksuits. Their faces were the faces of guys who in no way expected what they first saw—an ocean of soldiers and police, an entire army assembled to apprehend them.

Family members of Venezuelan migrants who suspect their loved ones were sent to El Salvador as part of a rapid US deportation operation over the weekend are struggling to get more information as a legal battle plays out.