The grandparents of one of two teenage girls slain during a winter hiking trip say they still believe investigators will find the killer. Fourteen-year-old Liberty German and 13-year-old Abigail Williams were found dead Feb. 14, a day after they vanished along a trail near Delphi. Liberty’s grandparents, Mike and Becky Patty, say they still have faith police will arrest whoever killed the Delphi teenagers.