The noise startled Alexis Bukrym. It was a crashing sound, near the front of her apartment, and a few seconds later, another noise twisted her stomach and rattled her nerves: the sound of her bedroom doorknob jiggling, then turning, and the door swinging open with a creak.

There’d been a series of car break-ins at the Ocala, Florida, apartment complex, and Bukrym and her neighbors worried that burglaries would come next. “Everybody in our community was on edge,” she said. “There’s a lot of bad people in the whole world, and a lot of people think, ‘It’ll never be me.’ But I’m cautious.”

Standing in the middle of her room on that Friday evening in April 2017, the lights on and the cloudy sky darkening out the window, Bukrym moved quickly, instinctively. A slightly built 23-year-old living away from her parents’ house for the first time, she’d prepared herself for the possibility of danger. As the door opened, she reached under her pillow for her handgun, a Ruger LCP .380, pointed it at the figure filling her doorframe, and pulled the trigger.

The bullet struck the man in the chest, and as he collapsed, Bukrym got a look at his face for the first time. It was her roommate, Anthony Schwartz. Bukrym dropped the gun and fell back against the wall in shock, and soon tears welled in her eyes.

“You remember every second of it,” Bukrym said in an interview. “The face he made. How he fell. We were best friends.”

Since 2015, at least 47 Americans have shot friends, loved ones, roommates, or emergency responders they said they’d mistaken for home intruders, killing 15, according to an analysis of gun violence incidents by BuzzFeed News and The Trace. In at least 27 of those cases, criminal charges were dismissed or never filed because authorities deemed the shootings accidental, an act of self-defense in a moment of panic.

For years, gun-rights advocates have promoted the use of firearms by arguing that “to stop a bad guy with a gun, it takes a good guy with a gun,” a refrain National Rifle Association executive vice president Wayne LaPierre repeated in a speech in late February. Pro-gun media outlets, like Bearing Arms, which has around tw0 million followers on its Facebook page, and Active Self Protection, which has more than three-quarters of a million subscribers on its YouTube channel, highlight cases of armed civilians warding off attackers. In the days following the February 14 shooting at Marjory Stoneman Douglas High School in Florida that left 17 dead and 14 wounded, President Donald Trump and others called on school districts to arm teachers for the safety of their students, an idea originally proposed by the NRA in 2012 after the mass shooting at Sandy Hook Elementary School in Newtown, Connecticut. “When a sick individual comes into that school, they can expect major trouble,” Trump said of the proposal during a White House press briefing. “The bullets are going to be going toward him, also.” Earlier this month, Florida passed a law allowing some teachers to carry guns in the classroom.

But good guys with guns don’t only shoot bad guys with guns. In the sudden, blurry, urgent split seconds when a threat bursts into view, the impulse to pull the trigger can overwhelm the need to accurately identify the target, leading to snap decisions that bring permanent tragedies.

As Schwartz, 21, lay on the floor, bleeding but conscious, Bukrym hoped her friend could be saved. She was crying when she called 911, explaining what happened between short, choppy breaths. She ripped a strip from her shirt and tied it around his wound. She wrapped a blanket around him. When he began nodding into unconsciousness, she slapped his face to keep him awake. She talked to him, telling him he was going to make it and that everything was going to be OK, but beating against the inside of her head was the thought that she had just fired the bullet that killed him.

Like Bukrym, most Americans who own guns got them for protection. A 2016 survey by researchers at Harvard and Northeastern universities found that 63% of gun owners said that self-defense was a primary motivation for owning a firearm — significantly more than cited hunting or other sporting use. Sales data reflect this: Since 1994, the number of long guns like rifles and shotguns — which are often used for hunting — owned by civilians rose by 21% while the number of handguns, more portable and easier to conceal, rose by 71%.

The national violent crime rate today is less than half of what it was in 1994, according to FBI statistics, but the drop in crime has barely altered Americans’ perception of their safety. A 2016 Pew Research Center poll found that 57% of registered voters falsely believed that crime had increased since 2008. Even as the threat of crime has sunk, the demand for weaponized protection has soared. From 1998 to 2005, fewer than one million pistols were manufactured each year in the United States; since 2012, at least three million have been manufactured annually, according to Department of Justice data.

Many of these handguns are in homes. Many never fire a bullet into a person. But that can change in a flash.

Derrick Fulton, of Grovetown, Georgia, awoke at 2:34 a.m. on Feb. 25, 2017, when he and his wife got an alert on their phones informing them that the front door had been opened. Their teenage daughter had sneaked in her boyfriend, then hid him in a closet when she realized her parents were out of bed. She told them nobody was there, but her father heard a noise coming from the closet. When 17-year-old Jordan Middleton burst out and broke for the front door, Fulton shot him.

“He’s trying to breathe, but I don’t think he’s going to make it,” Fulton told the 911 dispatcher, counting out chest compressions in the foyer, where Middleton had collapsed.

“He shouldn’t have been in my house!” Fulton wailed into the phone. He later told police he thought the teenager was an intruder about to attack him. Middleton was dead by the time emergency responders arrived.

In November 2016, Pauline Lloyd, 51 at the time, fatally shot her boyfriend, 50-year-old Kelvin Watford, inside their Trenton, New Jersey, home. She thought he was away on a business trip and that someone had broken in, she told the 911 dispatcher. “He’s dead. I can’t do anything. I can’t do anything,” she sobbed into the phone. “I’m sorry. I’m so sorry.”

Brandon Phillips, then 29, fatally shot his cousin Calem Copeland, a 24-year-old Army veteran, in October 2016. Phillips told investigators that he fired when Copeland jumped out from around a corner to try to prank him, according to an incident report from the Toombs County Sheriff’s Office in Georgia and the 911 call reporting the shooting. The hallway was dim and Phillips didn’t know his cousin was in the house, he said.

Harvey Benford, a 72-year-old living in Cincinnati, fatally shot his 14-year-old son, Georta Mack, in the neck one morning in January 2016. The boy had returned home to play hooky from school; Benford, startled to hear somebody in the house, mistook him for a burglar and pulled the trigger. Holding a piece of cloth to the bullet wound, Benford carried his son to the front porch so the EMS team could find them right away.

“Oh, God!” Benford screamed after realizing his son had stopped breathing. “Oh, God.”

After paramedics wheeled Schwartz into an ambulance, an officer drove Bukrym to the police station, where a detective took her statement.

She’d spent most of the evening drinking beer and Sake bombs with Schwartz and another friend at the apartment, she said. When the friend left, Bukrym retreated to her bedroom and Schwartz went outside to get something from his car. She assumed he was going out for the night.

“He normally says my name or knocks before coming in,” she said.

They’d been roommates for three months, having put their money together so they could each move out of their parents’ places. Schwartz worked retail at Sprint and Bukrym was a credit analyst for a food distribution company. “We both had decent jobs, had saved up, and wanted an adult apartment,” she said. They found a two-bedroom/two-bathroom near the mall, just off the highway, in a subdivision with two artificial lakes. “We never got furniture, just a couch and TV,” she said. “I had my bed on the floor, but it was my floor.”

Young adults eager to begin the next chapter of their lives, they cherished their newfound space and freedom. Bukrym described Schwartz as a joy to live with. He had a warm, positive vibe about him, did solid impressions of movie characters, and spoke excitedly about his interests, which included the Philadelphia Eagles and anime television shows. Some nights, the two played hangman on a whiteboard in the living room or sang songs while Schwartz played the guitar. “If you’re feeling down, he’ll get you motivated and hype you up,” Bukrym said.

On the night of the shooting, as Schwartz lay on a stretcher, he told officers the shooting had been an accident, that he’d meant to prank Bukrym and had scared her. Schwartz didn’t lose consciousness after taking the bullet, which gave Bukrym hope. It wasn’t until the next day that she realized how dire the situation was.

To stabilize Schwartz, doctors at the University of Florida Health Shands Hospital in Gainesville placed him in a medically induced coma. The bullet had pierced his liver, pancreas, and stomach. He suffered two aneurysms and underwent a blood transfusion. His heart stopped at one point. Surgeons removed his spleen and two-thirds of his stomach.

Racked with guilt, Bukrym rarely left her room. Whenever she stepped out to go to the front door or the bathroom, she passed the spot where Schwartz had fallen, and the moment replayed in her mind. Two weeks after the shooting, he remained comatose.

Bukrym shot a gun for the first time when she was 10. Under the supervision of her father, a racehorse jockey from South Carolina, she aimed the pistol at targets on her family’s rural property. “I grew up around guns,” she said. Her father had given her a year of safety lessons before allowing her to hold one.

As a teenager, she joined friends at the gun range. There was no question in her mind that she would eventually have a firearm of her own. At 19, she passed a class for a concealed-carry permit. At 20, she began putting money down for her first gun. At 21, she bought the Ruger LCP .380, which is small and lightweight.

Bukrym’s Ruger LCP .380 — the gun involved in last April’s shooting. Zack Wittman for BuzzFeed News

She kept the gun in a holster, hidden under her pillow on the corner of her bed. Schwartz knew she had it, but most days it remained out of sight. She’d taken to heart the lessons she’d learned from her concealed-carry class instructor: to “only take out your gun if you intend to use it,” she said. “The number one thing is you have to be prepared to take another life if it came down to it. You must be certain you’re OK with that. If you’re not prepared for that, you shouldn’t have a gun.

The handgun gave her peace of mind, she said. Schwartz didn’t own one, so Bukrym saw it as her duty to protect both of them. She saw her gun as a great equalizer, capable of turning the tables against bad people she wouldn’t otherwise be able to overpower. She was one of many who felt this way: A 2014 Gallup poll found that a majority of Americans believed that guns make homes safer.

She’d heard the stories in the news, and they followed the same arc: home invaders caught in the act by an armed resident who kills or wounds them before they can attack. Three weeks before Bukrym shot Schwartz, a man in Oklahoma shot dead three teenagers who’d broken into his father’s house with the intent to rob the family. Police found that the teens had brought a knife and brass knuckles. In June 2017, two armed burglars were killed by a Bay Area homeowner. In September, 79-year-old James Thomas Noah, of Winston-Salem, North Carolina, fatally shot a man who forced his way into his house and began beating him. And on Tuesday, an armed officer at a Maryland high school fired at a student who’d shot two classmates. The teenage gunman died.

FBI crime data shows around 290 legally justifiable homicides per year from 2005 to 2016, a majority of them by gun. But these incidents represent just one side of the ledger. In an analysis of the Gun Violence Archive, a database compiled from police blotters and media reports, BuzzFeed News and The Trace found a nearly equal number of self-defense and unintentional shootings from 2014 to 2017. A 2014 review of 16 gun violence studies, published in the Annals of Internal Medicine journal, concluded that a firearm in the home increased the risk of a household member dying in a gun homicide or suicide.

Part of being a gun owner, Bukrym said, was understanding that things could go horribly wrong, that accidents could happen, and that this risk was the cost of the protection. “There’s always a threat of somebody wanting to hurt you,” she said. “I would take that chance every day.”

Schwartz awoke from the coma near the end of his third week at the hospital. “The doctors were telling me, ‘Hey, listen, man, you could have died seven times in seven different ways,’” he recalled. Unable to speak, he communicated with his family by writing on a small whiteboard. He texted Bukrym to tell her that he wasn’t ready to talk to her yet, that he needed to figure out how he felt about what happened. He told police he didn’t want to pursue criminal charges against Bukrym.

On May 12, Schwartz left his first Facebook post since the shooting: “For those who don’t know I’ve been at [Shands Hospital] for a week and will stay here for over month. I lost a lot of my abdomen in a shooting. I can not physically speak due to a tracia in my neck but I wanted to let everyone know I was 👌”

He logged his progress in subsequent posts.

May 15: “I was over whelmed last week by the well wishes and thank you all so much I stay off my phone a lot when I’m here because it depresses me alittle so I’m really sorry if I didn’t get back to you.”

May 19: “Got a new tube in throat now I can talk!!”

May 21: “God I miss eating and drinking so much”

May 23: “Quick update. I no longer have a tracheae I am breathing and talking independently, i was just reintroduced to food and liquid today the transition to get me off the feeding tube started. Im finnaly on my way to being done at the hospital and moving on to rehab”

May 25: “I got discharged today!”

Schwartz posted inspirational videos and memes, and joked with friends about how he’d nearly been killed by a single bullet while 50 Cent “gets hit with shotguns .44 ARs a fucking rocket launcher and a nuke and was like out the hospital in 2 months.”

Schwartz shows the scars that cover his abdomen as a result of the shooting. The circular scar to the right of his belly button was the bullet entry point.

He was staying in his parents’ house, and he told Bukrym that he wouldn’t be returning to their apartment. She terminated their lease and moved back in with her parents.

After a few weeks, Schwartz texted Bukrym to discuss what happened, an intense exchange that lasted hours, picking up in the morning where they’d left off the night before. “We talked it out,” he said. “We burned it out over a couple of days. You can’t be best friends with somebody and just have that disappear. It was very important for the healing process to air out all the grievances and emotions.” Schwartz said that he forgave her. Months later, in December, they hung out for the first time since the shooting, meeting up at Bukrym’s new apartment in Orlando, where she’d recently moved.

Near the end of 2017, Schwartz finished his physical therapy. Doctors told him the only permanent damage to his body are the scars on his stomach and the missing spleen, which requires him to get annual vaccinations.

The ordeal changed how he felt about guns. Several months before the shooting, while Schwartz was working at a Sprint store, he was robbed at gunpoint. After that, he had decided he should start carrying a firearm, so he began putting money down on a Glock pistol. Weeks after Schwartz was discharged from the hospital, the gun was finally paid off, and the merchant said he could pick it up. He decided against it.

“Would I keep a gun in my house?” Schwartz said. “Hell, no. Everybody’s so paranoid right now. It’s a very volatile time, and with the fear we create inside our own heads, I don’t think I can trust myself to know who’s trying to cause me harm.”

Police had seized Bukrym’s gun at the scene, but returned it to her about a month after the shooting. She no longer keeps it under her pillow. Now she stashes it a few steps away from her bed. “A couple seconds’ leeway,” she said. It’s the one new precaution she’s taken since the shooting. The trauma of nearly killing her friend didn’t make Bukrym afraid of guns — “complete opposite,” she said. “It’s unfortunate it was my friend behind the door, but if it hadn’t been, I would have saved my own life and his, too. If somebody is busting through my door, I would pull the trigger every time.”