Teen Stabbed, Killed Girlfriend on Hike: Cops 16-year-old stabbed 17-year-old in throat By Ruth Brown, Newser Staff Posted May 27, 2013 5:13 PM CDT 34 comments Comments (Shutterstock) (Newser) – A 16-year-old Pennsylvania boy has been charged with stabbing his 17-year-old girlfriend to death while out on a hike. According to officials, the pair were arguing about his cell phone and her "going out" as they walked along a trail in Skippack on Saturday, when the boy, Tristan Stahley, pulled a knife and stabbed her in the throat and elsewhere, the Philadelphia Inquirer reports. A county assistant DA says Stahley stabbed her "so many times at this point that we do not have an exact count yet." He then dragged her body in the woods, and returned home, where he told his mother what he had done. The coroner's office ruled the death a homicide. "It's a tragic case," said the assistant DA. "This young lady was scheduled to graduate soon from her high school and was planning on going on to college."