Bradley Holt (pictured), the older half-brother of University of South Florida freshman quarterback Quinton Flowers, was killed in a random act of violence last week.The 24-year-old Holt was throwing a football around with local kids in Allapattah, a neighborhood in Miami, when a yellow Mustang showed up and started doing donuts in the street. Holt, worried about kids playing in front his apartment complex, walked over to the driver and asked him why he was "driving so crazy with so many kids out here?"The driver left. Holt's sister said the driver came back "about 15 to 20 minutes later" and fired two shots at Holt. One of them hit Holt in the back of the head, killing him.Then the driver, said to be in a 1988 or 1989 yellow Ford Mustang convertible, took off again. Police have since located the car, but are still looking for the driver.