(AP)- A background investigator erroneously failed to check a would-be trooper’s mental health history, allowing him to be hired for the Virginia State Police the year before he kidnapped a 15-year-old girl and killed three members of her family in California. The Virginia State Police superintendent wrote in a Dec. 30 letter to the state’s inspector general that the hiring of Austin Lee Edwards, despite his 2016 stay in a psychiatric facility, was “the direct result of human error” and appeared to be an isolated incident. Edwards had posed online as a 17-year-old boy while communicating with the 15-year-old girl in California. He killed her family last year after she stopped responding to his messages.