GREENBELT, Md. — A federal judge said Friday that it is “extremely troubling” that a government lawyer couldn’t explain what, if anything, the Trump administration has done to arrange for the return of a Maryland man who was mistakenly deported last month to a notorious prison in El Salvador.

The U.S. government attorney also struggled to provide any information about the exact whereabouts of Kilmar Abrego Garcia, despite Thursday’s ruling from the U.S. Supreme Court that the Trump…