Police discovered the bodies of a couple shot to death in their Fullerton home after their 34-year-old son, himself twice wounded by gunshots, made his way to a neighbor’s house, banged on the door and then collapsed. The son, Randy Ballusk, was listed in stable condition at UC Irvine Medical Center in Orange suffering at least two gunshot wounds, one to the chest and one to the hip, according to Fullerton police. His mother, Ruth Ballusk, 69, was pronounced dead on arrival at St. Jude Hospital in Fullerton, where she was taken by paramedics. His father, Edward Ballusk, also 69, was pronounced dead at the scene. Investigators found a small-caliber handgun in the house in the 1400 block of Sudene Avenue. Police declined to say if any suspects have been identified. Robbery has been eliminated as a motive in the early morning shootings, officers said.