John Schwartz:

“Pick your head up, buddy,” Tom Dunn said to Darius Nash, who had fallen asleep during the morning’s reading drills. “Sabrieon, sit down, buddy,” he called to a wandering boy. “Focus.”
Mr. Dunn’s classroom is less than three miles from his old law office, where he struggled to keep death row prisoners from the executioner’s needle. This summer, after serving hundreds of death row clients for 20 grinding, stressful years, he traded the courthouse for Martin Luther King Jr. Middle School.
The turmoil of middle school turns many teachers away, said the school’s principal, Danielle S. Battle. Students’ bodies and minds are changing, and disparities in learning abilities are playing out.
“A lot of people will say, ‘I’ll do anything but middle school,’ ” she said.
But this is precisely where Mr. Dunn chose to be, having seen too many people at the end of lives gone wrong, and wanting to keep these students from ending up like his former clients. He quotes Frederick Douglass: “It is easier to build strong children than to repair broken men.”