Teen-ager Fatally Stabbed: Police are investigating the fatal stabbing of a 17-year-old Santa Ana youth but have made no arrests or determined a motive. The victim, Savas Martinez, was discovered by the resident of a home in the 700 block of South Orange Street shortly before 8 p.m. Tuesday. The resident heard a knock on the door and called police and paramedics after finding Martinez slumped on her front porch, officers said. Martinez was treated by paramedics and transported to Western Medical Center in Santa Ana, where he died at 1:40 a.m. He had a single stab wound to the heart. Police spokeswoman Maureen Thomas said that no murder weapon was found and that it wasn’t clear where the stabbing occurred.