Avery Severson said she fears for her safety after the false accusation She was trying to start conservative student club at White Bear Lake High School After police and FBI investigation, officials said the messages were a hoax Student behind the slurs wanted to 'raise awareness of social and racial injustice' Authorities refuse to confirm the identity of the student behind the messages Superintended later apologized for using word 'hoax' saying he never intended to 'minimize the impact that racism or racist acts has on students'