Now that the Washington version is over, it’s time to dip back into a gun debate in which you might have more invested — the one in Georgia.

Before state lawmakers left Atlanta last month, they preserved a bill in a vat of amber — ready to be taken out and given final passage when they reassemble in January — intended to expand the list of places that concealed weaponry can be carried by those over the age of 21.

Included on that list, for the first time, would be the campuses of public universities. The Board of Regents is dead set against this. Gov. Nathan Deal intends to negotiate some sort of compromise in the next several months.

A few days ago, I received a furtive call from a ranking campus cop. “Parents don’t understand what’s about to happen,” he said. “Things have changed. They’ve rewritten the book.”

So there was a book.

That was something to track down, along with the fellow who wrote it. He’s John Kane, an affable retired police lieutenant from Sacramento. Fifteen minutes of conversation turned into 40, and by the end, this much was clear:

Set aside, if you will, the philosophical debate over whether private firearms belong on a university campus. You’re still left with a potentially dangerous clash of tactics between Second Amendment enthusiasts and a newly aggressive police approach to dealing with crazed gunmen. It’s something that state officials — not to mention parents — are obliged to take into account.

The conflict has been brewing for precisely 14 years — as of Saturday, the 14th anniversary of the massacre at Columbine High School in Colorado. That’s when two seniors turned their high school into a stalking ground, killing 12 of their fellow students and a teacher before committing suicide.

For gun rights advocates, Columbine was proof of the futility of assault weapons bans and gun-free zones. It fueled their demands for fewer restrictions on carrying.

But Columbine changed police, too. And this is where Kane comes in. Since the ’60s, police tactics in shooting situations had boiled down to “surround, contain and negotiate.” A ’70s TV series — “S.W.A.T.” — was even built around the law enforcement cliche.

“Then came Columbine,” Kane said. In 1999, cops surrounded the Colorado high school — and waited for negotiations that never happened. These two armed kids weren’t hostage-takers. They were hunters.

“Active shooter” was the cold phrase developed by Kane and others.

In this new world, officers arriving on the scene of a shooting in progress were now required to move in, quickly, and with one goal in mind — locating and isolating the fellow with the gun.

“We’re telling people now, if you’re the only one there, you have to go in. If there are only two of you, you have to go in,” Kane said. And nevermind the people lying on the ground around you.

“It’s horrible. We tell officers that we’re very sorry, but you must go in and bypass victims — as hard as that may be to step over people that are injured,” said Kane, who now consults on disaster preparedness.

In his textbook, one complicating factor in the “active shooter” scenario is the “freelancer.” When he wrote it, Kane was referring to the off-duty cop, out of uniform, rushing to the scene. University officials in Georgia — campus police chiefs, in particular — are worried that it could soon describe the heroic 21-year-old who doesn’t have the training to understand that a drawn gun in police presence can be something close to suicide.

“These are quick, horrible, dirty, rapid events that are over in five, 10, 15 minutes. These cops are going to be at the height of their awareness, armed to the teeth, running in at the absolute risk of their lives. And if you even hesitate for a second, you could be shot,” Kane said.

“There’s too much confusion, too much emotion, too much yelling and screaming. When you’re confronted by an officer — whether you have the right to carry or not — and that officer says drop your gun, you should drop the gun immediately.”

Flinch and die.

Kane is no gun hater. Concealed weapons are allowed on public campuses in his home state of California. But California requires 16 hours of training for all concealed weapons permits, including a practical demonstration of proficiency.

Senate Bill 101, the gun bill now hibernating in the bowels of the state Capitol, already would require students who pack to complete an eight-hour gun safety course.

Kane would suggest yet another round of mandatory training — given by the same police who patrol the campus where the gun will be toted. Just to give everyone a chance to know one another.

Additionally, he’d suggest university officials ask that students who carry concealed weapons submit a record of their carrying permit.

“One gun might have stopped Virginia Tech. I understand that,” Kane said. “And one guy might have stopped that guy in the movie theater in Aurora. But if you’re going to do that, you’re going to have to shoulder some very serious responsibility.

“It’s your moral and legal responsibility to know when to use that weapon, when to display it and when to put it down,” he said. “You can’t go running around the campus with a gun in your hand.”

Oh, about Kane’s book. It’s called “Critical Incident Response,” published by NorCal Publishing Services. If you’re a state lawmaker, order yourself a copy. Use campaign funds if you have to.