By Graham Lee Brewer Staff Writer gbrewer@oklahoman.comNORMAN — A man whose rape case helped spark a student-led walkout at Norman High School in 2014 was given an additional year of prison time Thursday for violating the terms of his sentence. Tristen Killman-Hardin, 20, was convicted of rape in 2015 for assaulting a Norman High School student.Read more on NewsOK.com