Puerto Rican ex-boxing world champion Hector "Macho" Camacho is clinically brain dead, doctors have said.
Family members were disagreeing on whether to take him off life support.
Dr Ernesto Torres said doctors have finished performing all medical tests on Camacho, who was shot in the face on Tuesday night.
"We have done everything we could," said Dr Torres, who is the director of the Centro Medico trauma centre in San Juan. "We have to tell the people of Puerto Rico and the entire world that Macho Camacho has died, he is brain dead."
He said at a news conference that Camacho would remain on life support until later today, at which time the family will have to tell doctors whether they want to donate his organs.
Dr Torres said Camacho's father has already indicated that he wants the boxer taken off life support and his organs donated, but one of his sisters opposes the idea. "This is a very difficult moment," he said.
Ismael Leandry, a long-time friend and former manager, told reporters that Camacho's mother also is wavering on taking her son off life support and would like more time with him. He said the family is waiting for Camacho's oldest son to arrive before having a family reunion and making a decision. "Let's remember him as a good man," Mr Leandry said. "He was a good father, a good son."
The 50-year-old Camacho was shot as he and a friend sat in a Ford Mustang parked outside a bar. Police spokesman Alex Diaz said officers found nine small bags of cocaine in the friend's pocket, and a 10th bag open inside the car. Camacho's friend, identified as 49-year-old Adrian Mojica Moreno, was killed in the attack.
Camacho was born in Bayamon, a city within the San Juan metropolitan area, but he grew up mostly in New York's Harlem neighbourhood, earning the nickname "the Harlem Heckler."
He won super lightweight, lightweight and junior welterweight world titles in the 1980s and fought high-profile bouts against Felix Trinidad, Julio Cesar Chavez and Sugar Ray Leonard. Camacho knocked out Leonard in 1997, ending the former champ's final comeback attempt.