Guns don’t kill people, teachers do.

At least that’s the intent of a bill introduced by state Rep. Phillip Lowe, R-Florence, that would give South Carolina teachers and other public school employees the right to carry guns on school grounds as long as they have concealed weapons permits. Lowe says the bill would be one way to protect kids if a school comes under attack.

“By having a weapon, we may be able to limit the carnage in an incident,” said Lowe. “You’ve got to have it so people don’t know who’s carrying a weapon, that anyone and everyone could be.”

This is part of the gospel of the National Rifle Association, which preaches that the only answer to gun violence is more guns. Wayne LaPierre, the NRA’s executive vice president, stated the golden rule last week in the wake of the school massacre in Newtown, Conn.: “The only thing that stops a bad guy with a gun is a good guy with a gun.”

What LaPierre fails to note is that too often it’s the wrong guy who gets shot.

The world doesn’t operate like an action movie or a violent video game. The real world is messier than that, and once the bloodshed has occurred, we can’t just go back to the beginning and start over.

Lowe and LaPierre know that the notion of vigilante teachers has a certain appeal in a nation that reveres the myth of the lone gunslinger bringing peace to frontier America. Teachers – or principals, cafeteria workers or armed police officers, as LaPierre suggested – instead of hopelessly huddling in a classroom, could use their guns to cut down any fiend who might harm the children.

But we have to consider how this might work in real life. For starters, putting a police officer in every school, as LaPierre proposes, would be prohibitively expensive.

However, if a school cop could have prevented the killings in Newtown, the cost would have been justified, right? But how exactly is the police officer supposed to identify which visitors to a school pose a danger to the children? How does the officer distinguish between a potential shooter and a relative of one of the students or some other harmless visitor?

And a school cop is likely to hesitate until an intruder makes his intentions clear. A shooter, especially one wearing body armor, will have the advantage, even over an armed on-campus officer.

Anyone who has watched a “Die Hard” movie might assume it’s relatively easy to hit the target you’re aiming at. That is a misconception.

In 2011, the New York Post compiled the record of New York Police Department shootings over the previous decade. During those 10 years, NYPD cops fired 4,702 bullets, accidentally pulled the trigger 323 times – and missed 78 percent of their intended targets.

In 713 reported incidents in which cops shot at civilians, the officer was the only one firing 77 percent of the time. So, presumably, they were shooting – and missing – even when no one was shooting back.

In August, New York police responded to a report of a shooting near the Empire State Building. When officers reached the scene, they fired 16 rounds on a crowded street. They killed the gunman but also wounded nine innocent bystanders in the process.

This is not meant to single out the NYPD. It’s officers probably are as competent as any.

The point is, they are professional law enforcement officers highly trained in the use of firearms – far more so than teachers who might have passed a state marksman test. And still they miss what they’re shooting at nearly 80 percent of the time.

If teachers start shooting inside a crowded school, they’re just as likely to hit a child or another teacher as an invader. And how would a teacher live with himself or herself after shooting a student?

Consider also how guns would change the working environment in schools. What’s to stop school employees from reaching for their guns during a dispute with a coworker or if they feel threatened by a student?

While the decision to carry a gun on school grounds supposedly would be up to individual employees, it is easy to envision reluctant teachers being pressured to get a permit and join the posse: “Don’t you want to help protect the students?”

It’s also important to remember that, despite the massacre in Newtown, schools by and large are among the safest havens for children anywhere. Many children are at far higher risk in their own neighborhoods, some in their own homes.

With the Newtown tragedy, the nation understandably is focused on school safety. But what about keeping children safe in movie theaters, malls, libraries, museums, amusement parks, at sporting events, swimming pools or church picnics?

Do we really want to encourage people to carry guns wherever they go, as the NRA advocates? Even if you believe citizens have a basic right to bear arms, that seems nonsensical, an invitation to mayhem.

Other nations have successfully chosen to regulate guns and have reduced gun violence as a result. Why can’t we?