A 21-year-old man has been arrested for shooting and killing a San Francisco Bay Area police officer Wednesday, authorities said. He is being treated at a hospital for gunshot injuries. Mark Estrada fired shots at Sgt. Scott Lunger at about 3:15 a.m. after being pulled over for rash driving, the Associated Press (AP) reported, citing Cpt. Mark Koller of Hayward police department. Lunger was reportedly rushed to Eden Medical Center in Castro Valley where he was pronounced dead.