Major advances in neuroscience since the 1990s helped convince the Supreme Court to rein in how we punish young killers.
Ethan Couch became known as the 'affluenza' teen during his trial for killing four people while driving drunk when a psychologist said he was so wealthy and spoiled he could not tell the difference between right and wrong.
Most of the detainees were over 18 years old but could neither read nor write.
In Neustrelitz Prison, administrators emphasize therapy and eschew the retributive impulse that has defined American justice for decades. Inmates even have rabbits and horses to look after.
"Kids are just going to fight to stay alive. They'll be hustling each other for meal trays."