Roanoke-CountyRoanoke County school board member Thomas McCracken already had a community meeting scheduled for next Monday night to discuss the sudden departure of Northside High School principal Frank Dent and assistant principal Amy Puckett – now a social media gun threat last night that some parents say they should have known about sooner will be a topic.  Roanoke County police determined that threat of gun violence was not credible – but it kept many Northside classrooms mostly-empty today. McCracken praised the job police and school personnel did in keeping students reassured that their school was safe.