El Salvador, a country of 6.2 million people about the size of New Jersey, has long had a role in US immigration. A civil war from 1980 to 1992 drove out more than a quarter of its population.

NEW YORK — A convicted double-killer from El Salvador has been arrested in New Jersey on a charge of “illegally reentering the United States,” prosecutors said. César Eliseo Sorto-Amaya was ...