Local law enforcement are investigating threats at two area high schools and alerting the public to an increased police presence on campus Thursday. Fairfax County Public Schools acknowledged a threat on social media toward Fairfax High School. "Police are actively investigating and additional officers are at the school," a brief statement noted. No other schools or facilities were impacted. The Stafford County Sheriff's Office is also investigating a threat circulating on social media toward a school with the initials "SHS." "Investigators do not believe the threat is credible," SCSO officials said in a statement. "Out of an abundance of caution,...