Did the "No Guns" sign stop a school shooting?

A teen was shot right outside of a high school in DC, which is fortunate because if he shot the teen inside of the school it would be twice as illegal as if it were done in some other school because of all of those effective gun laws. The only option then would be for DC lawmakers to make it three times as illegal, right?

Oh yeah! It's Ballou High school we're talking about. This seems to be a reoccurring theme there, and what was it that Mayor Fenty said about the last shooting?

"Any violence near any of our schools is unacceptable," District Mayor Adrian Fenty said. "We're going to find out who did this."

You mean you're going to "Get Them?" Normally you just play catch-and-release. Call me skeptical.