A 2009 study by the University of Pennsylvania found that assault victims carrying firearms were 4.5 times more likely to be shot than those who were unarmed. And when ordinary civilians were given police firearms training and put into a simulated mass shooting for the news show 20/20, most were so panicked that they couldn’t even remove their guns from the holsters, let alone take aim at the shooter. Even police officers often miss their targets and shoot bystanders by mistake. Trained New York City cops hit the “bad guys” only 18 percent of the time.

Yet the NRA claims that schools and colleges would be safer if students and teachers were armed. Pro-gun groups, including the NRA, are now pushing state legislatures to pass laws permitting guns at schools and colleges. They seem to be oblivious to the fact that their claim that “gun-free zones” invite violence runs directly counter to all evidence.

The reality is that no mass shooting has ever been stopped by an armed civilian. Perhaps it’s time to give up on that fantasy. Adding to the more than 300 million guns that we already have in our country will not stop the ongoing slaughters.

Morgan lives in Napa.