Authorities say a 15-year-old girl has been arrested on suspicion of killing another teenager whose body was found in an empty field in a remote Northern California town. The Mendocino County Sheriff’s Office says 16-year-old Ruby Sky Montelongo was found dead by her uncle Saturday morning. The sheriff’s office says investigators learned the victim had been assaulted Friday evening by a 15-year-old girl she knew from town. The 15-year-old was booked into Juvenile Hall and could face a murder charge. The results of an autopsy could take several weeks.