If there were a police officer inside of the school in this case then it would have at the very least been a road block in front of the crazy guy, no matter how small of a road block, that isn't the argument. The point is that an officer simply being there is going to do something to distract and/or delay the killer.
Also I am in no way advocating a TSA-type system. I think that the TSA hassles innocent and harmless people for no reason other than to give a false sense of security to people and make it seem like they are doing something good.
Do you really think more cops is the solution ? 1 police officer per school would be quite expensive and probably useless.... because as history shows, more policemen is less crime ?
Even IF there was a cop at the gates, with "unlimited entry search privileges" if i wanted to kill 20 kids, i would just wait (as someone pointed out) for the end of the school day....
Even tighter packed targets, shooting fish in a barrel ! As for the TSA... the most colossal waste of cash ever (unless of course you are high up and benefit from it).
And with 300M guns in the US, getting rid of guns is out of the question. And well criminals (and crazy fucks) will still find a way to get guns...
However as a criminal, if i know there's 0% chance of my target being armed (thus my life is not at stake) there's almost no reason to use lethal force (see japan's example).
Crazy fucks will kill people, it happens even France/Germany/Norway.... There's no cure for Madness/Evil (unless you imagine a big brother / 1984 scenario).
The real problem (at least for me) is the "Media Super Star" syndrome :
"Joe the Trucker" kills 10 because he fell asleep behind the wheel... at most you'll see a couple of lines in the papers, he's dead and forgotten.
"Jack the Psycho" goes in a school and kills 10 kids ? He'll share his pain/anger/fear and live forever ! Special Documentary, 200 hours live footage, Special Edition on CNN....
Fuck..... you'll even make Obama cry... Super Stardom !
Talk about going out with a bang and leaving your mark in history ?!?!