Camacho's family is considering whether to remove him from life support. More tests are going to be done, but late Wednesday Camacho showed irregular brain activity.
The 50-year-old was shot on Tuesday night as he sat in a car with his friend outside a bar in Puerto Rico. His friend, 49-year-old Adrian Mojica Moreno, was shot and killed.
Police said two assailants fled in an SUV but no arrests have been made and no motive has been disclosed. According to investigators, officers found nine small bags of cocaine in the friend's pocket, and a 10th bag open inside the car.
Camacho, who battled drugs and alcohol over the years, won world titles in the super lightweight, lightweight and junior welterweight divisions in the 1980s.
The Associated Press contributed to this report.