(Eugene, OR) -- A Corvallis man is accused of making threatening Twitter posts against Oregon State University. Authorities say 22-year-old Christopher Strahan allegedly tweeted that he was training for "shooting up OSU." The former OSU student has been charged with making threatening communications following the February messages. Oregon State Police report that Strahan was investigated a year earlier for similar threats. He was convicted of disorderly conduct, spent 20 days in jail and was committed to the state hospital for up to six months.