If the VT shooter had so many mental problems, why didn't someone commit him?

On another question I asked about gun control, people were saying this guy had mental problems, which is apparently true... Why didn't someone have him committed or at least evaluated for psychosis? Is it because nobody wanted to offend him? Also, if another student had had a gun, he could have been shot right away, end of story. The school will end up being sued by the families of the victims and rightfully so. They let this nutbag run around on their campus because they're so concerned about being warm and fuzzy, and then after he killed two people...they sent a friggin email?!?!?! Please. The blood is on their hands as well as his.