Personally, if I were one of your other students @@, seeing campus security (I assume you mean campus police?) would have no effect on me beyond wondering if there had been some incident with you. It would not worry me. If I even registered it at all, I'd probably assume someone had broken into your vehicle or something. I think the same would apply to this problem student if he notices, unless his issues include having bizarre or paranoid thoughts in which case who knows. Alternatively, if he is violent and is actually plotting something, he could momentarily fear he is under suspicion for something concrete. I doubt simply seeing campus police would forestall any action on his part, especially since it seems like he might have an issue with impulse control and making decisions based on taking responsibility for himself and having an eye to the consequences of his behavior.

Still, I doubt it would hurt - that is, unless he is paranoid and/or delusional and also violent, is plotting something and thinks he should act sooner rather than later because people may be growing suspicious, or something like that. But in those cases, he would certainly become violent at some point anyway.