Hindsight. We can look back now and see signs that COULD have tipped someone off, but still people do odd things occasionally and the vast majority don't go over the edge like this. You can't lock up EVERYONE who acts a little strange or moody once in a while.
IMO, there is really not much that anyone could have done to prevent this. It's just a matter of picking up the pieces and moving on and seeing what wwe can learn from it.
What amazed me, was at the press conference, Gov. Rendell said basically that some thing...that no amount of gun legislation; no wait periods, etc., nothing could have stopped the carnage...this surprisingly from the liberal, gun grabber, Fast Eddie. The killer had no prior police record. None.