Five things to know about one of the deadliest federal prisons

The Marshall Project and NPR investigated how the newest federal prison — the penitentiary in Thomson, Ill. — has quickly become one of the deadliest. The story is the latest in our years-long coverage of the dangers of "double-celled solitary confinement" — putting two people on lockdown in a small cell — as well as the use of force in federal prisons.

Here are five takeaways from our investigation.

Officials moved a notorious double-celled prison program to a new facility. The problems followed.

The "Special Management Unit" is a high security prison program meant for some of the most dangerous people in federal custody (though many for nearly 24 hours a day in a cell roughly the size of a parking space, forced to eat, sleep and defecate just feet from each other. In 2016, in that unit when it was housed in the penitentiary in Lewisburg, Pa.