I bought a lime-colored case for my iPhone recently, figuring the neon-green cover just might keep me from getting shot. At any other point in my adult life, I could reasonably be accused of paranoia for attaching such a morbid thought to a mundane purchase, but like most black men in America, I am often misjudged by police and civilians as a criminal threat. And these days, pulling Apple’s smoky “space gray” phone from my coat pocket -- in a store, on someone’s front porch or in a dark stairwell -- could be fatal.

It’s not just the recent plague of unarmed African-Americans who’ve died at the hands of police that has me anxious. I’m also deeply troubled by the growing number of Americans who are allowed to carry concealed firearms in public. In most U.S. states, gun owners with a permit can carry concealed weapons, and the number of public places they can take their guns is growing. A new Georgia law, for instance, expands carry rights to bars, schools and churches. The expansion of concealed-carry laws, combined with so-called Stand Your Ground statutes, seems to invite twitchy gun-carriers to act on unreasonable fears of black people in ways that are sure to endanger innocent lives.

In the two years since the tragic mass shooting at Sandy Hook Elementary School in Newtown, Connecticut, cries for expanded concealed-carry laws have grown louder. Proponents claim the solution to mass shootings -- and crime in general -- is public hypervigilance and more guns in the hands of law-abiding citizens. Supporters push the idea that bystanders carrying concealed weapons can minimize death tolls in mass shootings.

The National Rifle Association went so far as to promote a program to train and arm schoolteachers. “The only thing that stops a bad guy with a gun is a good guy with a gun,” NRA CEO Wayne LaPierre said at a press conference covered by NPR. The NRA’s campaign has been effective. Most Americans now favor gun rights rather than gun control, the Pew Research Center reported. This represents a stark change from two years ago.

My problem: I don’t trust the ability of gun-toting “good guys” to accurately determine who’s “bad.” A number of studies suggest that, even as racial tolerance improves, many Americans associate black people, especially black men, with danger. And average citizens -- even those who’ve passed the requirements to carry concealed weapons -- are not properly qualified to assess threats.

In a 2011 joint study by social scientists at the University of Chicago and the University of Colorado, researchers found “robust evidence” of racial bias in the decisions armed people make when they perceive danger. As part of the experiment, participants played a first-person-shooter video game that flashed real-life footage of young men. Some of the men held wallets or cellphones in their hands; others pointed guns. Half of the men (armed and unarmed) were black. Half were white. Participants were given little more than a half-second to respond by pressing one button labeled “shoot” or another marked “don’t shoot.” The object, of course, was to fire at anyone who poses a threat without harming the others.

The study found participants “typically shoot black targets, armed and unarmed, more frequently than white targets,” according to the researchers. “Even when participants respond correctly, they typically shoot an armed target more quickly when he is black, but in response to an unarmed target, they indicate don’t-shoot more quickly when he is white. Other researchers have obtained similar results using a variety of paradigms.”

A recent article in Mother Jones magazine about the science of racial prejudice highlights similar research. The message in the stilted academic language of the studies is clear -- and helps explain the recent shooting of 12-year-old Tamir Rice in Cleveland, along with countless others.

My concerns are also based on real-world experience. I don’t see myself as a menacing presence. In fact, if Barack Obama had a slightly younger brother, he’d look like me. Still, on a daily basis -- whether I’m dressed in a suit and tie, or T-shirt and shorts -- I confront instances of racial profiling that range from comically cliché to downright offensive. For many people, I’m a symbol of hazard in ill-lit subway stations, as well as on sunny suburban roadsides. I’m comfortable enough with myself to understand that people who flinch at me in elevators don’t really see me.

I cope by finding the humor in these situations, and, as long as my life and livelihood aren’t threatened, I often can. There’s an elderly South Asian woman in my suburban New Jersey neighborhood who takes her daily walk at about the same time that I arrive home from work. As we walk toward one another on the sidewalk, she inevitably steps out into the middle of the road, giving me a 50-foot-wide berth as she passes. She waddles along the road’s double-lined yellow median like a tightrope walker, making the calculation that it’s safer to brave the occasional car, truck or bus than it is to come within arm’s reach of me.

I can shrug off my neighbor. But at a time when more and more citizens are being encouraged to arm themselves -- with the implicit message that they’re empowered to take the law into their own hands -- how many of the people who would otherwise cross the street when they see me coming might pull out a gun because they feel threatened?

Concealed-carry expansion has another hidden danger for black Americans. Recent events and decades of research also show that even the best-trained law-enforcement officers can have trouble assessing danger in situations where race is involved. I worry about how the police might approach me and other African-Americans in those states where they might assume I’m carrying a legally concealed weapon.

The increasing calls for gun-carrying rights, the NRA’s encouragement of vigilantism, and the rise of so-called Shoot First laws all make for a world that’s a lot less safe for people like me. Even if gun carriers could save a few people in mass shooting incidents, those numbers could never offset the scores of black males killed by mistaken vigilantes. No parent ever wants to hear, “Sorry, I thought your son’s iPhone was a gun.”