The land of the free leads the world in incarceration. Why?

When Sylvester Shockley was 9 years old, he says he was arrested for breaking into businesses and sent to an “all-boys reform school” — what he later realized was a detention center for “juvenile delinquents.”

It was 1959, and his career as a defendant in the criminal justice system was just beginning. By the time Shockley was 14, he had been placed in a juvenile detention center for a second time, for another break-in. Shortly after he returned home, he says, he was back in the system again following a...