WASHINGTON -- A 23-year-old bank robber named Shon R. Hopwood stood before a federal judge in Lincoln, Neb. He asked for leniency, vowing to change.
Judge Richard G. Kopf had no patience for promises. "We'll know in about 13 years if you mean what you say," he said. It was 1999.
Judge Kopf reflected on the exchange this month. "When I sent him to prison, I would have bet the farm and all the animals that Hopwood would fail miserably as a productive citizen when he finally got out of prison," he wrote on his blog. "My gut told me that Hopwood was a punk -- all mouth, and very little else."
"My viscera was wrong," Judge Kopf went on. "Hopwood proves that my sentencing instincts suck."
Judge Kopf had just heard the news that Mr. Hopwood, now a law student, had won a glittering distinction: a clerkship for a judge on the United States Court of Appeals for the District of Columbia Circuit, which is generally considered the second most important court in the nation, after the Supreme Court.
Mr. Hopwood's remarkable ascent began in the prison law library, where he became not only a good jailhouse lawyer but also a successful Supreme Court practitioner. Persuading the justices to hear a case is a roughly 100-to-1 proposition, but the court granted the first petition Mr. Hopwood filed.
The case, about whether the police had crossed a constitutional line in questioning a suspect in a drug conspiracy, caught the attention of Seth P. Waxman, a former United States solicitor general. He said Mr. Hopwood's petition, on behalf of another prisoner, was one of the best he had ever read. Mr. Waxman agreed to argue the case before the justices on the condition that Mr. Hopwood stayed on the team.
They won, 9-to-0.
I first wrote about Mr. Hopwood in 2010, when he was working as a paralegal in Omaha and thinking about law school.
Since then, he was granted a full scholarship, financed by the Bill and Melinda Gates Foundation, to the University of Washington School of Law in Seattle. He has published a book, "Law Man: My Story of Robbing Banks, Winning Supreme Court Cases and Finding Redemption."
During his first two summers at law school, he served as an intern for a federal judge and at a public defender program.
The judge Mr. Hopwood worked for last summer said he deserved his 147-month sentence. "He used a weapon in some of those robberies, and that justified a very heavy hit," said Judge John C. Coughenour of Federal District Court in Seattle. "But everybody we sentence has the potential to turn their life around."
"When I took him on, I thought there might be some reservations around the courthouse," he said. "People might have been concerned about having a convicted felon and former inmate privy to all the confidential materials around here. There was never the slightest objection."
After he graduates next year, Mr. Hopwood will serve as law clerk to Judge Janice Rogers Brown on the federal appeals court here. Judge Brown did not respond to a request for comment.
Judge Kopf, who sentenced Mr. Hopwood, also declined to talk, on the interesting theory that "such interviews could be seen as backhanded endorsements of the media companies" requesting them. Mr. Hopwood turned down an interview request, citing his impending clerkship.
But Mr. Hopwood and Judge Kopf have conducted an extraordinary public dialogue on the judge's blog, "Hercules and the Umpire."
"I wouldn't say that your sentencing instincts suck," Mr. Hopwood told the man who sent him away. "I was a reckless and selfish young man back then. I changed."
He added, though, that his sentence had been too long. "From my experience," he wrote, "sentences over five years do little to help society or the prisoner." Longer sentences rob prisoners of hope, he wrote, discouraging them from preparing for a new and productive life.
Mr. Hopwood said he did not blame Judge Kopf, who merely applied the law. But he did say that not everyone in his shoes gets a second chance, and he posted a link to a 2012 article he had written in The Atlantic about a prisoner named Adam Clausen.
"Although our crimes were similar," Mr. Hopwood wrote in the magazine, "a federal judge sentenced Adam to 213 years of imprisonment; his release date is Dec. 1, 2185."
Judge Kopf agreed with Mr. Hopwood's basic point. "I have thought for a long time that 60 months was about the maximum sentence one should impose if you were solely hoping to make a positive impact on the prisoner," he wrote.
The exchange occurred on Aug. 8, and it was in a way prescient. Four days later, Attorney General Eric H. Holder Jr. announced an initiative to address long prison terms required by mandatory minimum sentences.
"Too many Americans go to too many prisons for far too long, and for no truly good law enforcement reason," Mr. Holder said.
Mr. Hopwood and his accomplices committed very serious crimes, stealing some $200,000. No one was hurt, but he and his accomplices "scared the hell out of the poor bank tellers," Judge Kopf said at the sentencing in 1999.
Mr. Hopwood is 38 now, and married with two small children. Assuming he is granted a license to practice law notwithstanding his crimes, his future looks very bright.
"My original dream," he told Judge Kopf, "was to become a paralegal, not law school, and definitely not a future clerk on the D.C. Circuit."
"I feel fortunate that I have been given so many second chances, including the sentence which allowed me to be released at a fairly young age," he said.
In all, he said, "I received a large dollop of God's grace."
This article originally appeared in The New York Times.