From the blurb on youtube.com for this video:

Published on Apr 21, 2010

The controlled study documented in these videos show that concealed carry permit holders are fooling themselves if they think they will be able to react effectively to armed aggressors. Most CCW holders won’t even be able to un-holster their gun. They will more likely be killed themselves or kill innocent bystanders than stop the aggressor. For more details, see “Unintended Consequences: Pro-Handgun Experts Prove That Handguns Are a Dangerous Choice for Self-Defense.” http://www.vpc.org/studies/unincont.htm.

CCW permit holders don’t protect innocent people. They kill them.

Part 1 – 9.5 minutes

Part 2 – 3.5 minutes

One other thing you have to remember: police entering a shooting scene will not be able to determine a good guy with a gun from a bad guy with a gun. If a person has a gun, they would be suspect immediately.

Making teachers handle weapons will cause huge problems for the teachers and the schools. The best solution is much stricter gun controls.