(Beaverton, OR)  --  Beaverton police say a social media post containing a threat against Southridge High School has been deemed not to be credible.  Authorities say the anonymous threat on the After School app said "I'm shooting up the school," but it was removed from the app by the time police were contacted around 9:25 yesterday morning.  Authorities and school district officials say there was no evidence of any danger to students or staff.