On the 13th of March, 1996, 18 people were killed in the Dunblane school massacre here in the UK. This caused a host of hard line gun ownership restrictions to be implemented including, most notably, the banning of hand guns. Since then, there has been one school related attack in the UK. The attacker used a knife and although 7 people were injured, nobody was killed.
Since the 13th of March, 1996, there have been 59 shootings in American schools (including elementary, middle, high and university). There have also been a few (about 3 or 4) attacks involving knives. In total, 146 people have been killed in these attacks (including deaths of shooters where applicable) and 210 people have been injured.
That means that since 1996, 18 people have died in the UK in school related attacks. By comparison, 146 have died and 210 have been injured in the USA in school related attacks.
Surely, therefore, the focus should be on stopping whatever is causing so many attacks to happen in the USA as opposed to the UK rather than attempting to arm students in the event of such attacks. All I can say is that after Dunblane, we could have taken the route of arming our students but we didn't and it appears to have been the right route to take because there has not been a single death in a school in the UK since.
Edit: I should also note that in 3 (I think) of those 59 incidents, the shooter was stopped because another person in the vicinity owned a gun. Deaths or injuries still occurred in all of these incidents before the shooter could be stopped but the other gun owner being there undoubtedly saved lives.
CNN ran a story today that said that the 4 campuses in the US that have allowed concealed weapons for a combined total of 60 months to date have yet to have one incident of any kind.
In the UK, no student or teacher is allowed to carry a gun on campus. In every single university in the UK, at least since 1996 (i.e. 132 months) there has never been a single gun related death or injury.
Of the campuses in America in which no guns are allowed, what percentage of them have had gun related deaths or injuries?