Guns are like a grandmother’s diamonds in the Reichert family, heirlooms that carry memory and tradition. They are used on the occasional hunting trip, but most days they are stored, forgotten, under a bed. So when Kameron used one on himself, his parents were as shocked as they were heartbroken.

“I beat myself up quite a bit over not having a gun safe or something to put them in,” Mr. Reichert said. But he said even if he had had one, “There would have been two people in the house with the combination, him and me.”

The gun debate has focused on mass shootings and assault weapons since the schoolhouse massacre in Newtown, Conn., but far more Americans die by turning guns on themselves. Nearly 20,000 of the 30,000 deaths from guns in the United States in 2010 were suicides, according to the most recent figures from the Centers for Disease Control and Prevention. The national suicide rate has climbed by 12 percent since 2003, and suicide is the third-leading cause of death for teenagers.

Guns are particularly lethal. Suicidal acts with guns are fatal in 85 percent of cases, while those with pills are fatal in just 2 percent of cases, according to the Harvard Injury Control Research Center.

The national map of suicide lights up in states with the highest gun ownership rates. Wyoming, Montana and Alaska, the states with the three highest suicide rates, are also the top gun-owning states, according to the Harvard center. The state-level data are too broad to tell whether the deaths were in homes with guns, but a series of individual-level studies since the early 1990s found a direct link. Most researchers say the weight of evidence from multiple studies is that guns in the home increase the risk of suicide.

“The literature suggests that having a gun in your home to protect your family is like bringing a time bomb into your house,” said Dr. Mark Rosenberg, an epidemiologist who helped establish the C.D.C.’s National Center for Injury Prevention and Control. “Instead of protecting you, it’s more likely to blow up.”

Still, some dispute the link, saying that it does not prove cause and effect, and that other factors, like alcoholism and drug abuse, may be driving the association. Gary Kleck, a professor of criminology at Florida State University in Tallahassee, contends that gun owners may have qualities that make them more susceptible to suicide. They may be more likely to see the world as a hostile place, or to blame themselves when things go wrong, a dark side of self-reliance.

Health officials in a number of states are trying to persuade families to keep guns away from troubled relatives or to lock the weapons up so teenagers cannot get them. Some of those same officials say the inflamed national gun control debate is actually making progress harder because the politics put gun owners on the defensive.

“You just bump up against that glass wall, and barriers go up and the conversations break down,” said B. J. Ayers, a suicide prevention specialist in southeast Wyoming.

Seeking to lower death rates, health departments in Missouri, Wyoming and North Carolina are giving out gunlocks. In New Hampshire, about half the gun shops put up posters and give out fliers alerting gun owners to the warning signs for suicide and suggesting ways to keep guns from loved ones at risk of harming themselves. A coalition of firearm dealers in Maryland is now planning a similar program.

“This is an issue whose time has come,” said Keith Hotle, state suicide prevention team leader for Wyoming, the state with the highest suicide rate. A state advisory council recently bumped firearms safety to the top priority in a new report to the governor on suicide prevention. But Mr. Hotle cautioned that in Wyoming, where guns are like cars — just about everybody has one — direct arguments against them simply will not work.

“The framing is important,” he said. “It’s not about taking away people’s guns. It’s about how to deal with folks in a temporary crisis.”

Kameron’s crisis was, by all accounts, temporary. He was a popular football player with adoring parents and no history of depression. He worked after school at the only corner grocery store in Dayton, a tiny town in northeastern Wyoming with tidy, tree-lined streets and a park at the base of Bighorn National Forest. He liked to drive students around in his Pontiac Grand Prix, and he always bought multipacks of gum at Costco so he could give out sticks in pretty blue wrappers to girls at school.

“If someone had a hankering for a hamburger, he’d be off,” said his mother, Cara Reichert, an administrator in the local school system.

The event that preceded his death in 2008 seems like the mischievous scrape of a teenage boy. Out one night in the town park, he was caught with a package of cigars by local police officers.

His parents are still tormented over the bad luck that followed. The officers searched him because they were training a new colleague. Then a clerk at the local court told him — incorrectly — that his parents had to be present to pay the fine. His parents punished him by taking away his cellphone, though they left him his car.

“If just one little piece of this story would not have fallen into place,” Mr. Reichert said, his voice breaking.

Suicidal acts are often prompted by a temporary surge of rage or despair, and most people who attempt them do not die. In a 2001 study of 13- to 34-year-olds in Houston who had attempted suicide but were saved by medical intervention, researchers from the C.D.C. found that, for more than two-thirds of them, the time that elapsed between deciding to act and taking action was an hour or less. The key to reducing fatalities, experts say, is to block access to lethal means when the suicidal feeling spikes.

The chances of dying rise drastically when a gun is present, because guns are so much more likely to be lethal, said Dr. Matthew Miller, associate director of the Harvard center. Guns are used in more than half of all suicide fatalities, but account for just 1 percent of all self-harm injuries treated in hospital emergency rooms, a rough proxy for suicide attempts, Dr. Miller said. Overdoses, which account for about 80 percent of suicide attempts, are responsible for just 14 percent of fatalities.

“If you use a gun,” Dr. Miller said, “you usually don’t get a second chance.”

One common argument is that the suicidal person would have found some other way to kill himself, even if no gun was available. That is the belief of Sharon Wells, the adoptive grandmother of Kyle Wells, a 16-year-old in Cody, Wyo., who shot himself with her pistol in October.

“It’s not the guns, it’s the person,” Ms. Wells said.

Kyle was born into a world of problems that began with fetal alcohol syndrome, and continued throughout school, where he was bullied relentlessly for his small stature, she said.

If he had not used a gun, she said, he would have used something else.

“Yes, many may find another method,” said Catherine Barber, director of the Harvard center’s Means Matter public health education campaign, “but will it kill them?”

Citing statistics from emergency rooms and death certificates, she said, “Nearly everything they substitute will have lower odds of killing them, sometimes dramatically so.”

Reducing access to lethal means has worked in other countries. An intervention in Israel preventing soldiers from taking their guns home on weekend leave, a time when many soldiers’ suicides occurred, helped reduce the suicide rate among them by 40 percent.

Michael Richins, a coroner in Lincoln County in southwest Wyoming who lectures on suicide prevention, contends that it is gun owners, not the government, who will bring down suicide rates. Gun control, which is about restrictions imposed by government, will only turn them off, he said. “You have to use an approach that’s palatable to people,” he said. “You’re not victimizing, you’re empowering.”

After Kameron’s death, his father could no longer stand to have the gun his son used in the house, so he gave it to his brother. Still, he cherishes his gun collection, and strongly opposes talk of gun control in Washington.

“I will always believe in guns,” he said.

He has sought solace in comforting others, reaching out to other families in the area who were going through a similar trauma. His life is still a fog of unanswerable questions: What if he had not punished Kameron by taking away his cellphone? What if he had locked up the family guns?

His daughter, Kassidy, a high school senior, tries not to ask such questions. Sometimes she feels angry at her brother, but mostly she misses him.

“It hurts even more to think what could have happened,” she said, “because it’s not going to change anything.”