An assault like that would have landed Mr. Harris behind bars in many countries, but not for nearly so long. Prisoners serve significantly more time in the United States than in most industrialized countries. Sentences for drug-related offenses and other crimes have gotten stiffer in recent decades, and prosecutors have become more aggressive in seeking longer terms — as Mr. Harris discovered when he saw the multiple charges against him.

For injuring two people, Mr. Harris was convicted on two counts of assault, each carrying a minimum three-year sentence. But he received a much stiffer sentence, of 15 to 45 years, on a charge of armed burglary at the crack den.

“The cops knew I was selling but couldn’t prove it, so they made up the burglary charge instead,” Mr. Harris contended. He still considers the burglary charge unfair, insisting that he neither broke into the crack den nor took anything, but he also acknowledges that long prison terms were a risk for any American selling drugs: “I knew other dealers who got life without parole.”

As it was, at the age of 24 he was facing prison until his mid-40s. He urged his wife to move on with her life and divorce him. Despondent, he began snorting heroin in prison — the first time, he says, that he had ever used hard drugs himself.

“I thought I was going to lose my mind,” he said. “I felt so bad leaving my wife alone with our daughters. When they were young, they’d ask on the phone where I was, and I’d tell them I was away at camp.”

His wife went on welfare and turned to relatives to care for their daughters while she visited him at prisons in Tennessee, Texas, Arizona and New Mexico.

“I wanted to work, but I couldn’t have a job and go visit him,” Ms. Hamilton said. “When he was in New Mexico, it would take me three days to get there on the bus. I’d go out there and stay for a month in a trailer near the prison.”