I Believe this would potentially be a mistake because there is no way to know for sure who of these teachers could be trusted with the responsibility and who could snap and any second and shoot up the whole class room. As bad as that sounds the possibility is quite real as we all know. Even individuals who have a long history or being a upstanding citizen and doing nothing but good have gone bad on occasion. I think a better idea would be to have more law enforcement/police present in these locations. That way these things could be monitored more closely and maybe even prevented all together. Most people (not all) that carry out these horrible acts wouldn't do so in the presence of a police officer. Its not a completely full proof plan but i see it being more beneficial then arming the teaching staff.