Will Armed Teachers Stop School Shootings?

The National Rifle Association is suggesting every school have at least one armed police officer and some schools are already arming teachers to protect students just in case there's a shooting incident. There are scenarios where an armed officer could stop a shooter, but a solution like this poses more of a problem in the long run. We've seen trained cops end up tasering kindergarteners when they get out of control so imagine what an armed guard or teacher would do with a gun when fights broke out or a student started getting out of control. This also doesn't seem like a good idea because any shooter would know there were guards and either try to take them out first or avoid them altogether while managing to kill as many as if there were no guard at all. But on the bright side at least grades and test scores might go up since students are more likely to pay attention to their teacher when they've got a loaded AK-47 slung over their arm. Kids in Nazi Germany did pretty well in school didn't they?