SCOTTSDALE, Ariz. — Pat English, a lawyer with long and influential ties to boxing, was delivering a history lesson on various federal guidelines for the sport when he flashed a black-and-white photograph of a young fighter.

The boxer’s name was Stephan Johnson, a junior middleweight who had fought three times (and most likely sustained at least one brain injury) in the seven months leading up to his United States Boxing Association title fight against Paul Vaden in November 1999. Johnson was under a medical suspension that was not recognized by some local boxing commissions, and despite his trainer’s objections he was eager to return to the ring so he could earn enough money to move his mother out of public housing.

Johnson lost the fight, and his life. Knocked out in the 10th round, he was rushed to a hospital where surgeons drilled two holes in his skull. He died two weeks later at 31.

English, who was at that fight, recalled some of those details last week as he spoke at a meeting of the people who regulate the sport and are grappling with fresh tragedies that feel too familiar.