resigned, over claims he didn't sufficiently address racism on campus, and after members of the football team said they wouldn't play until the president was out. we reported here yesterday, in one posting, police say park wrote online, and i quote, some of you are all right. don't go to campus tomorrow. the "associated press" reports the investigators asked the students where that was based on a threat posted before the shooting at umpqua community college. the student responded, uh-huh. then they asked, why? and he said, i don't know. i just -- deep interest. >> i mentioned the arrest happened days after missouri's president stepped down. students protested, saying he didn't address incidents of racism on campus. now we're seeing similar demonstrations in schools across the country. trace gallagher has more. mizzou just named on interim