Police in the Puerto Rican city of Bayamon say they found drugs inside the car in which former world champion boxer Hector "Macho" Camacho was shot and critically wounded.
Police spokesman Alex Diaz says the man shot and killed with Camacho was in possession of nine small bags of cocaine. A 10th bag was open inside the car.
Camacho and friend Adrian Mojica Moreno were shot as they sat in the parked car. The car belonged to Mojica. No arrests have been made and police have not disclosed any possible motive.
Camacho was shot in the face and doctors said he was in serious condition but expected to survive.
The bullet apparently struck him in the jaw but exited his head and lodged in his right shoulder and fractured two vertebrae, Dr Ernesto Torres of the Centro Medico trauma centre said. The doctor said the boxer, who was trailed by drug and alcohol problems during a career that included some high-profile bouts, could be paralysed from the shooting.
"Camacho's condition is extremely delicate," he told Telenoticias. "His physical condition will help him but we will see."
No arrests have been made in the shooting, police said.
Camacho representative Steve Tannenbaum said he was told by friends at the hospital that the boxer would make it.
"This guy is a cat with nine lives. He's been through so much," he said. "If anybody can pull through it will be him."
The fighter's last title bout came against then-welterweight champion Oscar De La Hoya in 1997, a loss by unanimous decision. Tannenbaum said he was going to fight two years ago in Denmark until his opponent pulled out and that they were looking at a possible bout in 2013.
"We were talking comeback even though he is 50," he said. "I felt he was capable of it."
Camacho was born in Bayamon, one of the cities that make up the San Juan metropolitan area. He won super lightweight, lightweight and junior welterweight world titles in the 1980s.
Camacho has fought other high-profile bouts in his career against Felix Trinidad, Julio Cesar Chavez and Sugar Ray Leonard. Camacho knocked out Leonard in 1997, ending what was that former champ's final comeback attempt.
Camacho has a career record of 79-5-3, with his most recent fight coming in 2009.
Drug, alcohol and other problems have trailed Camacho since the prime of his boxing career. He was sentenced in 2007 to seven years in prison for the burglary of a computer store in Mississippi. While arresting him on the burglary charge in January 2005, police also found the drug ecstasy.
A judge eventually suspended all but one year of the sentence and gave Camacho probation. He wound up serving two weeks in jail, though, after violating that probation.
Twice his wife filed domestic abuse complaints against him, and she filed for divorce several years ago.