Just like the Virginia Tech case, the college knew he was dangerous/unbalanced (had to call campus police multiple times) yet they did nothing.
Not what the college says. Apparently they sent they letter, suspended him and met with him and his parents.
"Loughner and his parents met Northwest Campus administrators October 4, 2010. During this meeting Loughner indicated he would withdraw from the College.
Pima did something, they kicked him the hell out. With help from the police, which means the police got a folder of data on him.