A father was arrested for investigation of murder in the shooting death of a 78-year-old man who had shot and wounded his 2-year-old son in the face. Floyd Atkins, 27, of Los Angeles was driving down Main Street near Martin Luther King Jr. Boulevard with his son, Chris, when he saw a man accosting a woman on the sidewalk with a pistol, Los Angeles Police Lt. Charles Massey said. When Atkins intervened, the gunman turned and fired at Atkins' car, hitting the child in the cheek, Massey said. The father jumped out of the car, took the weapon away from the assailant, identified as Glossie Hershey, and shot him, Massey said. The woman, apparently a friend of Hershey's, was not hurt. The 2-year-old was reported in fair condition at County-USC Medical Center.