Kevin Sanders said he was sorry for punching the elderly man in the jaw.

The D.C. Superior Court judge said she believed Sanders, then sentenced him yesterday to the maximum 3 1/3- to 10-year prison term, explaining that he is lucky that the maximum isn't longer.

Judge Noel Anketell Kramer, reciting a list of Sanders's previous assaults, said he should have known better than to attack 80-year-old Michael T. Brophy. The retired New York auto worker never recovered from the punch, dying three months later.

"You have an explosive temper, Mr. Sanders," Kramer told him, noting earlier attacks on his mother, schoolmates, a police officer and the mother of his child. "Until that changes, you present a very serious threat to the community. . . . I can't let you out."

Sanders, 19, pleaded guilty to aggravated assault in January. He had emerged from a crowd to attack Brophy on Pennsylvania Avenue SE on Oct. 29. Brophy, traveling north to New York from Florida, had run a red light at 15th Street SE. His car crashed into a 17-year-old pedestrian, Tantelya Gales, at an estimated 15 to 16 mph.

Brophy pulled over and got out to see what had happened. He approached the crowd that had gathered around Gales, who later recovered from a broken pelvis and facial cuts and returned to school within two months.

Sanders, who apparently did not witness the accident, asked who the driver was. Without warning, he slugged Brophy, fracturing both sides of the man's jaw. As Brophy fell, his head hit a car and then the concrete, leaving him in a coma. Although Brophy regained limited consciousness, prosecutor Sima F. Sarrafan said, he never spoke or walked again. He developed infections and died of a heart attack Jan. 25.

"Our loss is not a loss just for today or tomorrow or next week. It's a loss forever. He was everything to all of us," Brophy's widow, Karin, told the judge. "What he can't see. What we can't see with him. There are no eyes to replace him. His life is gone. That's our life, too."

Defense attorney Charles O'Banion argued that Sanders deserved a youth act sentence, which gives prison authorities greater flexibility in determining when an inmate should be released. O'Banion called his client's attack "a stupid and dumb thing . . . a cowardly act," but he said Sanders "did not intend to really hurt Mr. Brophy."

O'Banion cited what he called Sanders's "atrocious" juvenile record and recalled that Sanders had told him, "As a youngster, I was beaten up so badly, I learned to fight and then I became the aggressor."

"He knew that lady," O'Banion continued, referring to Gales, "and he felt that someone had come into his community and done something wrong in his neighborhood. He has a ninth-grade education. He's only 19 years old. He has one 3-year-old child. He has no discernible skills. But he's young, and he has his whole life ahead of him."

Speaking softly when his turn came, Sanders said he felt worse than anyone in the courtroom. "I know I was wrong," he said, explaining that he "wasn't even thinking" when he threw the punch. The former Southeast Washington man declared himself sorry and said he would accept Kramer's judgment.

The judge described Sanders's remorse as "an excellent first step" and concluded that there was no racial element in the attack of the young black man on the elderly white man. She sent him to prison and advised him to think carefully about what he had done.