such instances are rare and not prevented by police control. If one wanted to do the same as what was done at any one of the "school shooting tour" http://www.tshirthell.com/shirts/tshirt.php?sku=a03 schools at a school such as mine with 1 cop, one could quite easily, without even bringing a gun to school. get 3 guys, aproch the cop in his office, tackle his ass, kick him a bunch of times, steal his gun, kill as many as posible before more cops show up. one way to protect people from crazy fucks like "one" is to not have a cop at all. Another way is to have 100 cops with ak-47s. both have the same result