What do Seung-hui Cho and James Holmes have in common?
Both are/were nuts.
And trained professionals knew it in both cases.
And yet both were able to walk the streets.
And slaughter the innocent.
See "The psychiatrist treating the accused Colorado movie theater gunman was so concerned about his behavior that she mentioned it to her colleagues, saying he could potentially be a danger to others."
See "On December 13, 2005, Cho was found 'mentally ill and in need of hospitalization' by New River Valley Community Services Board."
While politicians and law enforcement fret over little metal object that go bang ...
... madmen walk the streets.