Schools in a dozen Missouri school districts are taking a page out of the air marshals’ handbook. In response to the tragic shooting at Sandy Hook Elementary School, select teachers are being trained as armed responders. As CBS Evening News reports:

It may look like target practice at a police academy, but these men and women are teachers. They're learning to defend their students against an increasingly common threat: a school shooting.

Their faces cannot be shown because they're the classroom equivalent of an air marshal on a plane.

They carry their weapons anonymously.

When the semester begins, only the local police and school board will know they're armed.

An administrator says she chose to go through with the training because she's "from a rural school. And the response time is so slow to get any law enforcement help … I felt it was important, if I was able to help and do something to protect our kids."

In Missouri, local school boards decide whether faculty can be armed.

Twelve of the state's districts employ teachers who are getting weapons training at Shield Solutions in West Plains.

Former Highway Patrolman Greg Martin runs the program. "We've taken people who have never really handled a handgun at all and given them this training and turn them out to where they score a 90 percent." …

"We make it as realistic as possible because in the event that that happens, god forbid, we want them to be ready," says Martin.

The Second Amendment guarantees the right to bear arms. This right should not stop at the schoolhouse door. Nine states have passed laws allowing school teachers to be armed. Though controversial, empowering teachers to protect themselves and students is preferable to leaving them defenseless.