And he raised the provocative question of whether Martin himself, if he had been armed and of age, "could he have stood his ground on that sidewalk" and shot Zimmerman if he felt threatened when being followed.
Seeking to inject a sense of hope into his otherwise somber remarks, the president said race relations in the United States have improved with each passing generation. He said his young daughters and their friends are "better than we were."
"We're becoming a more perfect union," he said. "Not a perfect union, but a more perfect union."