The number of homicides committed using guns has gone up by nearly a third nationwide in recent years, according to new data from the Centers for Disease Control and Prevention.
The CDC found a 31 percent increase in homicides involving firearms from 2014 to 2016. In 2014, 11,008 homicides involved a gun. The number rose to 14,415 by 2016, the CDC team said.
Guns were by far the most common weapon used in homicides, the CDC team found.
"In 2016, the number of homicides involving firearms was approximately eight times the number of those involving cutting and piercing (1,781) and approximately 30 times those involving suffocation (502)," the CDC team wrote in the agency's weekly report.
The CDC regularly reports bare-bones statistics. The latest report is based on death certificates.
It also regularly reports on gun deaths,but its role in researching the underlying causes has been limited by the so-called Dickey Amendment, which is tacked on to congressional funding legislation every year. It bars the CDC from using federal funding to "advocate or promote gun control."
There's no question that the U.S. leads the world in gun deaths, but there's disagreement over how much of a role is played by the high rates of firearm ownership in the U.S. and the relative lack of regulation on who can buy guns and what kind of weapons are available. One study in 2015 found that one in three Americans owns a gun.
Daniel Webster, a gun policy expert at the Johns Hopkins Bloomberg School of Public Health, said one surprising factor behind the recent increase in gun killings is the outcry against police killings of unarmed people.
Gun deaths went up in Baltimore, he said, alongside the unrest that followed the 2015 death of Freddie Gray in police custody. Police pulled back from much of the day-in, day-out patrolling they had been doing in many parts of the city. "That kind of policing activity dropped substantially," Webster said.
"Policing was preoccupied with quelling the riots. There is evidence of a pullback of general policing activities by Baltimore police," Webster, who wrote a detailed report on the effect in January, told NBC News.
"When you add a breakdown in trust between communities and police, I think that is a recipe for more violence."
Webster also noted that more states were loosening rules on gun ownership and the carrying of guns around the same time that firearms homicide rates went up.
"Regulation of permits became more relaxed," he said. That's true — all 50 states now allow concealed carrying of weapons, compared with 31 in 1981. And 12 states allow concealed carrying without a permit.
"More people are walking and driving with guns because they feel unsafe. They don't feel the police can protect them," Webster said.
Several groups, including a team at the Harvard School of Public Health, have linked the free availability of guns with a rise in gun deaths.
Opponents of gun control often argue that someone bent on killing someone else will find a way to do it. But Webster noted the CDC's data showed that killings using a knife or by suffocation were far lower than deaths by firearms.
"If your sole objective is to kill someone, the very logical thing is to use a firearm," Webster said.
"It is far more successful. You can have literally dozens of stab wounds and survive if they don't hit the right place on you. The amount of tissue damage from a gunshot wound is so dramatically different from the tissue damage of someone stabbing you. Weapons matter."
The CDC data did not include firearms deaths other than homicides. Most deaths involving guns in the U.S. are suicides. The CDC says 36,252 people died by firearms in 2015, and of those, 22,018 were suicides.
"The fact is, even more than depression or substance abuse, the strongest predictor of how likely a person is to die from suicide is a gun in the home," Dan Gross, president of the Brady Center and Campaign to Prevent Gun Violence, said in a 2016 report.