Police said two males were riding bicycles near San Marino Street and New Hampshire Avenue about 1:20 p.m. when one of them was hit by a car.
A passenger got out and shot the bicyclist, 19-year-old Shaoyan Almazan, who was struck and on the ground, leaving him dead at the scene. Police said they are certain the bicyclist was being pursued by the suspects in a white SUV.
"The suspects, three of them, one driver, two exited the vehicle and shot the victim where he laid," said Los Angeles Police Sgt. Rudy Lopez.
Residents said they heard about 15 gunshots. The second bicyclist tried to escape but was also shot in the hand. He was later found in the 800 block of Vermont Avenue in stable condition.
Police said the SUV fled down New Hampshire Avenue. Anyone with information was asked to call (877) 527-3247.