If you carry a gun, are you morally obligated to use it when confronted with a mass shooting? The latest horrific school shooting challenges Americans to look at the ethics of gun ownership.

With a six-minute video posted on Facebook, Scott Pappalardo became the face of the ethical gun owner to many Americans.

Looking at the camera just three days after Nikolas Cruz allegedly killed 17 people at a Florida high school, Pappalardo said, “The barrel of this gun will never be pointed at someone,” then sawed his cherished AR-15 in half.

Pappalardo, who lives in New York, is not the only gun owner who was motivated to get rid of an AR-15-style weapon after the Valentine's Day massacre in Parkland, Florida.

Florida resident Ben Dickmann surrendered his AR-57 to his local sheriff's office, saying, “No one without a law enforcement badge needs this rifle.” In California, a father who was assembling the gun with his son turned in his gun, too.

But the ethical questions that have been raised in the aftermath of America's most recent mass murder go beyond whether civilians should own semiautomatic weapons.

They include whether someone who carries a gun is morally obliged to use it when confronted with a crime in progress, as in the case of the officer who was outside Marjory Stoneman Douglas High School while Cruz was killing teenagers inside. Another is whether schoolteachers should be armed to defend their students, a policy President Donald Trump has pushed.

There are deeper questions, too, that challenge gun enthusiasts like Pappalardo, as calls for stricter gun laws grow louder. Some ethicists talk about the importance of bridge building and compromise, while defenders of current policies say personal freedom and the right to defend oneself and one's family in a fallen world supercede other virtues. (Even robots, after all, have a right to self-defense, some people say.)

Responsible gun ownership is about education, safes and trigger locks, among other things. What does ethical gun ownership look like? And what should people thoughtfully consider before making the decision to buy — or keep — a gun?

'Part of our normal'

For Pappalardo, ethical gun ownership involved cutting up his AR-15, an act which, as Popular Mechanics magazine later pointed out, made the still-usable weapon illegal.

Pappalardo has since given the remains of the gun to his local police department, and he told the Deseret News he wishes he'd spent more time researching the best way to destroy it. But he remains firm in his belief that giving up the gun he'd had for about 30 years was the right thing to do.

“Is the right to own this weapon more important than someone's life? … I don't think so,” he said.

The AR in AR-15 stands for ArmaLite Rifle, not assault rifle. The firearm was originally designed in the 1950s for military use, and today's version is similar to the military's M16. The NRA's blog called it "America's most popular rifle" in 2016, but that may be changing. Dick's Sporting Goods, a nationwide chain based in Pittsburgh, announced Feb. 28 that it would no longer carry assault-style weapons or high-capacity magazines, tweeting that "thoughts and prayers are not enough."

Pappalardo came to the same conclusion after the Florida shootings.

A building-material salesman, Pappalardo fits the profile of the typical American gun owner as described by Pew Research Center in a 2017 report: He's a white male who grew up with early exposure to guns. He was 18 when he had the Second Amendment tattooed on his arm.

“My father was an avid Western-watching man, and guns were always part of our normal. We had a summer house in the country, and we were taught to shoot at a young age. I've always had a respect for firearms and really enjoy shooting them,” he said.

Pappalardo retains a number of shotguns — the number and style of which he did not want to reveal — but he has unambiguous standards for their storage and use.

"First of all, all your rifles should be legally owned and legally registered, where required. All should have trigger locks on them, and all firearms should be secured. Personally, I keep mine in a gun safe," he said.

"You should never have a loaded weapon sitting around; any responsible gun owner would tell you the same thing."

Yet, according to a recent study published in the Journal of Public Health, more than half of U.S. gun owners say they keep at least one firearm unsecured.

Gun owner's dilemma

In Pew's 2017 report, two-thirds of gun owners said they bought guns for protection, which presents an ethical quandary: How do you simultaneously have a gun handy to protect your family from an intruder, while keeping it secure and sometimes unloaded?

For some gun owners, the answer is to store their guns in high-tech, biometric safes that open swiftly to a stored fingerprint.

Others, like Darin Kendall, operations manager for Impact Guns, adjust their habits to the current circumstances of their lives. Kendall and his wife are grandparents, and young children are often in their home, which is why his guns are locked in a safe if he's not using them.

“The chances of you getting attacked are very small; the chances of a 5-year-old getting a hold of the gun that you left on the table are much greater,” Kendall said.

Kendall works for a business that says it carries more handguns, AR-15 rifles, ammunition and other firearms than any other gun dealer in America. A gun owner “forever,” he shoots for pleasure and hunts, and he concedes that some people might call him not just an enthusiast but a “gun nut.”

His thoughts about gun ownership, however, carry the gravity of someone who understands that things can sometimes go wrong. The most important thing people should do before acquiring a gun, he says, is educate themselves about the risks. “A lot of people probably aren't really ready when they actually buy a firearm," he said.

“Guns are pretty easy to get if you're a citizen who hasn't been arrested or have felonies, but I think people should think about it a little more than they do sometimes. To me, an ethical gun owner is someone who tries to educate the people around them. They share their passion about firearms, and they share it in a way that's educational.”

Parents, even if don't have guns themselves, should talk to their children about gun safety since they could encounter firearms at a friend's house, he added.

Children and guns

Days after the Florida shooting, a study about gun prevalence and storage in families was published in the journal Pediatrics. Researchers found that gun storage practices and the presence of guns were about the same whether or not a teen at risk for mental-health problems lived in the house.

Suicide was the second-leading cause of death among children 10-17 in 2015, and guns were used in 4 of 10 deaths, according to the Centers for Disease Control and Prevention.

Daniel Webster, executive director of the Johns Hopkins Center for Gun Policy and Research in Baltimore, noted that in many of the recent mass shootings, the shooter did not own the gun or guns used but had taken them from family members. (Parkland was one of the exceptions; Cruz was a legal gun owner.)

“In my mind, responsible gun ownership, particularly if you have young children or teenagers, begins with securing your guns so they can't access them,” Webster said, adding that the issue goes beyond school shootings, since accidents and suicides account for most children killed or injured by guns.

According to the nonprofit Gun Violence Archive, at press time, there had been 560 children under the age of 18 injured or killed by guns in 2018.

D.R. Smith, a veteran and former law enforcement officer who lives in Park City, Utah and is a firearms instructor, said ensuring that children can't get to your gun isn't just an ethical mandate, but the law. "If a child gets your gun, you're going to prison," he said.

States with the strictest requirements for gun storage have some of the lowest teen suicide rates, according the Giffords Law Center to Prevent Gun Violence. In Massachusetts, where all guns have to be in a locked case when not in use, guns are used in 9 percent of youth suicides, compared with 39 percent nationally, the center says.

Utah does not have any laws governing gun storage and does not require permits and licensure to own a gun. To obtain a permit to carry a concealed gun, people must take a four-hour "firearms familiarity" course and pass a criminal background check.

Good versus evil

Conversation about ethics and guns is often steeped in language of the Wild West, according to the author of a paper titled "Gun Owners, Ethics and the Problem of Evil," published in the Journal of Ethnographic Theory in 2017.

Joe Anderson, an anthropologist at the University of Edinburgh, spent 15 months over the course of four years interacting with gun owners in San Diego, who also taught him how to shoot. He describes a community that embraces a worldview of good guys and bad guys, with the responsibility of protecting the larger community falling to the good guys with guns. They inhabit, he writes, "a morally charged guardianship of the spaces within which they move."

To people passionate about guns, giving them up is akin to turning the world over to monsters, Anderson said. That helps to explain Pew's finding that three-quarters of gun owners say they can't imagine ever not owning one, and also the arguments of AR-15 owners who don't want a world in which only bad guys have this type of gun.

Gun owners in America are more likely to be evangelical Christians, who are also more likely to feel safer with a firearm around, according to Christianity Today magazine, reporting on religious components of the Pew data.

But the conversation about the ethics of gun ownership is more complicated than a story about good versus evil, said Mark Ryan, who teaches ethics at the University of Dayton in Ohio and has written about the “clash of narratives” in American gun culture and Christian ethics.

The Christian worldview is based on the idea that we're living as God's companions and inviting strangers and even enemies into friendship, he said.

However, “To some degree, our gun culture in America trades on this idea that we're all on our own, that we should first of all see our neighbor, the stranger we may meet, as hostile to us. That comes out of an idea that freedom is fundamentally about being left alone. When we're arming ourselves, we tend to identify others as potential threats,” Ryan said.

The classic Christian virtue of prudence, therefore, is an essential component of gun ethics, he said.

"In its premodern form, prudence is not just being cautious, but being really wise. What we would hope is that whatever discipline, whatever formation, goes along with somebody being a responsible gun owner or gun user, it would be such that they would be able to refrain from its use in the event that they couldn't be sure that they weren't going to do more harm than good."

It's that uncertainty of what happens when a gun fires that makes gun policymaking so highly charged, even among gun enthusiasts. Trump wants to train and arm teachers to make schools more secure, but both Pappalardo, in New York City, and Webster, at Johns Hopkins, believe that's a bad idea.

“You're asking a teacher to carry a tremendous amount of responsibility, and in the event of a shooting, they're reacting to a shooting, not preventing a shooting," Pappalardo said. "By the time they're aware of the situation, shots have already been fired. And in an extremely stressful situation like that, your ability to aim properly is diminished. God forbid the teacher kill a student; how would the teacher be able to live with that?”

According to Pew, 44 percent of Americans personally know someone who has been shot, either intentionally or accidentally.

Webster noted that the debate over arming teachers focuses on mass shootings and rarely touches on more likely outcomes.

“How many hundreds of thousands of schools are there across America, and every single day, there are conflicts between students, conflicts between teachers, all kinds of risky and reckless behavior. You interject guns into those scenarios, and people are going to end up being shot,” he said, citing the 2014 case of the Utah teacher who accidentally fired a gun in a bathroom at an elementary school.

As for the question of whether someone who carries a gun is ethically obliged to use it in an event like a mass shooting, Smith, the firearms instructor in Park City, Utah and a former police officer, said if the person is in law enforcement, the answer is yes, because he or she has sworn an oath to protect lives.

For private citizens, who have not taken an oath and lack the specialized training that those in the military and law enforcement have, it's not clear-cut. In Sutherland, Texas, last year, a civilian armed with an AR-15 chased the assailant who killed 26 people at First Baptist Church, wounding him and leading to his capture. Kendall of Impact Guns, however, said getting involved is a personal decision, not a moral obligation.

"Even if you were a proficient firearms handler and trained soldier, and you did react to something like that, things can still go wrong, and you're putting yourself in a situation where you could be personally liable," he said.

"Everyone likes to think, yeah, I could be the hero if that was needed, but all of us aren't heroes. I've never been in a situation like that, so I couldn't tell you what I would do. I don't think anybody knows until they're actually put there.”

Gun owners and would-be gun owners also have to decide if they are psychologically equipped to deal with the prospect of ending another person's life, even if they did so to defend their family, as a Springville, Utah, man did in 2012.

In law enforcement and the military, people are taught to regard killing as "just business," Smith said. Civilians can't have that attitude, but they prepare mentally, up to a point, for the idea that "if it's between your family or them, or you and them, they lose," he said.

As the country recovers from the latest mass shooting and again begins debate on what to do to try to prevent another, Webster, at Johns Hopkins, said the conversation, to be effective, should be driven by not just data, but the values that Americans bring to the table.

Ryan, at the University of Dayton, said to reach consensus, we need to think about freedom in loftier ways, not the "thinned out" concepts that people often employ.

"Theologians sometimes call this thinned-out conception 'negative freedom.' It means getting external obstacles out of the way so that I can do whatever I want. That's fine as far as it goes, but to get the kind of conversation we need — one that promotes our country's common good — we need a positive concept as well," he said.

"Positive freedom acknowledges that we become fully free — that is, people of good character — in relationships of accountability with other people. To be a virtuous gun owner you have to be a good human being, not just technically good with guns."