The Republic | azcentral.com Wed Jan 15, 2014 7:23 PM

Cops and robbers is not a game for amateurs.

Yet we hear a lot these days from people who advocate an armed citizenry for the sake of public and personal safety.

Recent events at Arrowhead Towne Center in Glendale provided a more realistic view of the public and personal dangers of this approach.

The situation looked like it was crying out for an armed civilian hero.

A bad gal was apparently menacing a loss-prevention officer with a gun.

A good guy with a gun stepped in and fired four times.

The bad gal and her husband were not stopped. They got away, only to later be arrested by Glendale police.

The armed citizen who opened fire thankfully didn’t kill or wound any innocent bystanders. That was pure luck. A witness said a bullet went by her. She later found a bullet hole in her car.

The would-be hero, 61-year-old Mervin Brewer, may face charges for unlawfully discharging a weapon in city limits. The Maricopa County Attorney’s Office will make that determination.

According to reports, he saw an altercation between the couple and a guard. Then he saw his wife leave the store and head toward the trouble. So, he fired.

It’s hard not to feel sympathy for Brewer. He said he was scared for his wife’s safety and the safety of the security guard.

“I wouldn’t have wanted to take no one’s life or nothing,” he told 12 News, “but that’s kind of up to God to decide who lives and who dies.”

Bullets flying through the air do increase the chances of someone dying, however. Opening fire in a public place works in the movies.

In real life, it’s far riskier. And more complicated.

The bad gal’s gun turned out to be a toy. Oops.

Brewer had the best of intentions. But those who step in to play cop don’t have the training or understanding of public safety that’s drilled into police. They don’t have the expertise to handle situations that might turn deadly — or the practical judgment to know the best course of action to preserve life.

Brewer is a former Marine. He knows weapons. But military men and women are not taught the nuances of crime in the local parking lot. That’s a cop’s job.

Arizona makes it easy to carry weapons into public spaces. That’s a right many people take seriously for the sake of protecting themselves and their family. It’s their choice.

But many people take it a step further and argue we’d all be safer if more people were armed. This story is an example of why that is simply not true.

A trained police force is the best protection against crime, not a shoot-out in the mall parking lot. Police officers are trained to assess and de-escalate dangerous situations, not shoot first and figure things out later.

They are human beings, and they make mistakes. But they have been taught to respond with reason, not anger or fear. That increases the likelihood police won’t start firing as innocent people are going about their business.

An armed man waiting for his wife in the parking lot can easily misjudge a situation, see a pretend gun as a real threat and, by his own actions, put lives at risk.