Saturday, Oct. 12, a person in Fort Worth called the city’s non-emergency line because he was concerned about his neighbors, 28-year-old Atatiana Jefferson and her 8-year-old nephew. It was the middle of the night, but her front door was open. The dispatcher sent police officers, who appear to have treated the call as a reported burglary. While searching the perimeter of the house, Officer Aaron Dean saw a figure in the window. Without announcing himself, he yelled “Put your hands up! Show me your hands!” Two seconds later, he fired his gun, killing Jefferson in her own home.

The Fort Worth Police Department released a photo of a gun they claimed to have found in Jefferson’s house, a clear attempt to head off criticism. As of yet, there’s no indication that Jefferson was holding the gun when she was shot. And, of course, even if she had been, there’s nothing illegal about having a gun in your home in Texas. If Jefferson had been holding it, it was likely because she saw men with flashlights prowling around outside her home.

In June, just a few months before Jefferson’s death, the U.S. Court of Appeals for the 5th Circuit refused to dismiss a lawsuit against another Fort Worth police officer. In that case, the police were responding to a burglary call, but went to the wrong house. When homeowner Jerry Waller saw activity outside his house, he grabbed a gun and went out to see what was going on - and then ran into a Fort Worth police officer. According to police, the officer ordered Waller to drop his gun. He put it down on a car, but then reached for it again, at which time the officer fatally shot him.The police narrative makes little sense. Waller was on his own property, and did nothing wrong. It’s hard to fathom why he would knowingly try to kill a police officer. The police narrative also doesn’t quite fit the wound patterns on Waller’s hands, which appear to be inconsistent with someone holding a gun.

No reasonable person would suggest that either of these officers started their shifts intending to kill someone. Nor would any reasonable person suggest that then-Dallas police officer Amber Guyger went home from work intending to kill Botham Jean. You can say the same for the Southaven, Mississippi, police who responded to the wrong house, then shot and killed Ismael Lopez in his own home. Or for the Florida officers who shot and killed Andrew Scott, also after responding to the wrong house. Same for the officers who killed David Hooks, Jason Wescott and Andrew Finch. And those who killed Terence Crutcher, Philando Castile and Stephon Clark.

In fact, if we could somehow read the minds of all the officers involved in these cases, I wouldn’t be surprised if we learned that all of them sincerely feared for their safety. The problem is that not one of them was actually in any danger. Nor were the countless officers who shot someone (usually a black male) after claiming to have seen a suspect reaching for his waistband - only to discover the suspect was unarmed. There have even been cases in which a police officer shot a fellow undercover officer, then claimed to have sincerely feared for his safety.

The law permits the police officers to use lethal force if they have a reasonable fear for their safety or for the safety of others. Courts have consistently held that, when considering the potential liability of a police shooting, we should consider only the facts known to the officer at the time. That’s understandable. We can’t hold police officers accountable for information they didn’t have.

But reasonable isn’t the same thing as legitimate or accurate. And if police officers are seeing threats where there clearly are none, it makes sense to start asking why.

This is where the rhetoric of police groups and their supporters comes in. Law enforcement advocates such as the National Rifle Association, police unions, conservative politicians and, of course, President Trump regularly tell us there’s a “war on cops.” They describe police work with words usually reserved for the battlefield. They fuel the mistaken belief that relatively rare incidents such as roadside ambushes are common. They equate criticism and oversight of police with violence. And they cite small increases in the number of police fatalities year to year with percentages without providing the proper context - that violence against law enforcement has dropped to the point where even small increases look large when expressed as percentages.

One could argue that some of this would be harmless if its only effect was an excess of caution — if it made police officers more careful, led to more spending on gear like bulletproof vests, or caused more cooperation with police to solve violent crimes. But deaths such as Atatiana Jefferson’s show that the effects of such demagoguery are far more pernicious. We tell officers they can use lethal force when their fear is reasonable, but we then define “reasonable” down by falsely telling them that present-day America is a war zone, that protest and criticism is violence, that danger lurks around every corner. It creates a false reality where almost any use of force seems reasonable. This is a problem for everyone, but it’s compounded for black people, given the ample evidence that people of all races tend to disproportionately fear and see criminality in blacks - especially black men.

The NRA, in particular, has amplified the “war on cops” rhetoric, likely because it counts a lot of law enforcement officers among its members. But, as the cases above illustrate, legal gun owners should be more worried about this than anyone. An armed populace patrolled by hair-trigger police officers is a recipe for tragedy - and it’s all the worse if those officers have been conditioned to see threats where none exist. We’re all human. We will all make mistakes. Police officers will be sent to the wrong house. Some people will have mental-health crises. Someone will mistake the police officers outside his home for criminal intruders. Such incidents shouldn’t end in death. They too often do.

The “war on cops” rhetoric perverts the mental calculations officers make in these volatile moments by weighting them toward violence. When you’re inundated with messages that you’re perpetually under attack, every gesture starts to look furtive, every twitch looks like a killer reaching for his waistband. And when officers make these sorts of mistakes, we tend to reward them for their courage, which only reinforces the “shoot first” state of mind.

But often, courage is holding your fire. Courage is absorbing the risk of waiting an extra moment or two to gather more information before making a decision that may well save yourself but could also do irreparable harm to an innocent person. Courage is taking the extra seconds to learn that the “gun” you feared is actually a toy, or a cellphone, or a video-game controller. Or that the person you’ve mistaken for a threat has made the mistake about you. Courage is accepting the risk of not shooting the silhouette in the window, even though it might be a threat - because it’s much more likely that it isn’t.

Radley Balko writes for The Washington Post.