The idea is horrific, and, unfortunately, it can be inevitable. When bullets are flying everywhere, from time to time, one of the good guys accidentally shoots another good guy.

It now seems that the officer killed in the line of duty at the Borderline Bar & Grill in Thousand Oaks was an example of friendly fire.

What happened next is every officer’s worst nightmare: One of the patrolman’s bullets hit his fellow policeman, piercing his heart and killing him.

That [Sgt. Ron] Helus was killed by friendly fire emerged for the first time at a somber news conference Friday, exactly one month since 28-year-old [killer’s name redacted] attacked country-music lovers at the Borderline Bar and Grill in the Los Angeles suburb of Thousand Oaks, killing 12 and wounding 22 others.

[The killer], who wasn’t hit by either officer’s gunfire, fatally shot himself after the firefight.

Officials didn’t have much else to update about the investigation Friday, nothing more on the motive or the exact timeline of events – just the news that broke all their hearts, most of all that of the patrolman, who learned of the terrible mistake for the first time Thursday.

“I delivered the message to him … He had no clue it was coming,” said L.D. Maples, chief of the California Highway Patrol’s coastal division. “It surprised all of us. He’s devastated.”

The patrolman was only identified as a nine-year veteran of the department. He is on leave.

“We’re trying to take care of him right now,” Maples said.

Officials did say that Sgt. Helus was wearing his body armor, but didn’t say where he was hit.

Now, attention will turn to the officers who fired the fatal shot, and my heart goes out to the guy. I’m sure someone will belittle him, saying he should have been surer of his target and all that, and I get it. But I also suspect none of the people who have been involved in actual gunfights are saying that.

While I’m not part of that number, I’ve spent a lot of time talking to those who are. If they’re willing to share those experiences, and many aren’t, then I’m willing to listen and try to learn from it.

One thing I learned is that when the bullets are flying, it’s a lot easier to say things than to do them. It’s a dynamic environment where you’re trying to shoot the bad guy, not get shot yourself, and make sure innocents aren’t threatened.

Frankly, horrible things happen.

The officer who pulled the trigger on that fatal round will now be dealing with this for the rest of his life. He’ll have to come to terms with it, with the idea that he killed a fellow officer. It won’t matter that it wasn’t intentional. Well, it will, but it won’t help. If anything, it’ll make it worse. This officer is going to need to be taken care of, probably for a while. I don’t know that I’d go back in uniform under the circumstances, but I hope he’s stronger than that.

The fact of the matter was that when the bullets started flying, he didn’t hide. He went to fight, unlike some I can think of. I’d hate to see someone willing to put their life on the line for others leave because of one tragic mistake that could have happened to anyone.

If anything comes out of this, I hope it will be that departments will start to make force-on-force training more of a priority for its officers.