In the wake of the massacre at a small-town Texas church on Sunday, many people are asking why.
A large portion of the mass shootings in the U.S. in recent years have roots in domestic violence against partners and family members. Depending on how you count, it could be upwards of 50 percent.
We know the Texas gunman, Devin Patrick Kelley, was court-martialed for assaulting his wife and their young child in 2012, although this information apparently was not included in the formal government database that tracks such things.
There are laws on the books preventing convicted domestic violence offenders from obtaining weapons. So why does this keep happening?
There are no easy answers. NPR's Alison Kodjak recently talked with Daniel Webster, director of the Johns Hopkins Center for Gun Policy and Research in Baltimore, Md., about the complexities of gun violence, mass shootings, and the difficulty we have in understanding the people who commit these crimes.
While perpetrators of domestic violence account for only about 10 percent of all gun violence, they accounted for 54 percent of mass shootings between 2009 and 2016, according to the advocacy group Everytown for Gun Safety, so there is a disproportionate link, Webster tells Kodjak.
"Generally, it fits a pattern of easy access to firearms of individuals who have very controlling kind of relationships with their intimate partners and are greatly threatened when their control is challenged," he says.
And yes, there are laws preventing convicted abusers from getting guns, but there is a "girlfriend loophole."
"In our current times, many young people put off marriage for many years," he says, and these domestic partners aren't protected by many existing laws that are largely aimed at spouses and children.
There are a few obvious signs that someone is considering mass murder.
"Individuals who are amassing a number of weapons and a large amount of ammo, that obviously is a red flag. Individuals whose violence generally extends beyond the family would be an indicator of greater danger," Webster says.
But even though mass shootings have become more common over time, it's hard to pull together a specific profile that fits every shooter.
The Las Vegas shooter, who killed 59 people last month, didn't have a record of domestic violence and didn't show obvious signs of mental illness, Webster adds.
"Look, this is imperfect science — this is social science — predicting a relatively rare phenomenon in large populations of people," he says.
DAVID GREENE, HOST:
We now know that the man who killed 26 people in a tiny Texas church on Sunday had been court-martialed and discharged from the Air Force for assaulting his wife and child. And authorities say that Devin Patrick Kelley sent threatening text messages to his mother-in-law, who was a parishioner at the First Baptist Church in Sutherland Springs, Texas. That fact makes the Texas killer sadly typical. More than half of the mass shootings in the United States are related somehow to domestic violence. Our Health Desk has been part of the team covering this story, looking at domestic abuse and gun violence. And we want to turn first to NPR's health policy correspondent Alison Kodjak, who's in the studio. Hi, Alison.
ALISON KODJAK, BYLINE: Hi, David.
GREENE: So research shows that people who commit mass shootings are likely to also be involved in domestic violence. How certain and strong is that link?
KODJAK: It's a pretty strong link. The advocacy and research group Everytown for Gun Safety did a study that shows 54 percent of mass shootings are related to domestic violence, meaning the shooter killed his wife, his girlfriend or had some history or even, you know, with another family member, a former partner. I spoke with Daniel Webster who runs the Center for Gun Policy and Research at Johns Hopkins University, and this is what he had to say about it.
DANIEL WEBSTER: Generally, it fits a pattern of easy access to firearms among individuals who have very controlling kind of relationships with their intimate partners and are greatly threatened when their control is challenged, basically.
KODJAK: So Webster says that only 10 percent of all shootings involve domestic violence, so it's really overrepresented in these mass shootings.
GREENE: Which is extraordinary because aren't there laws to keep people like Kelley from getting guns? There's a federal law that bans people convicted of domestic violence from buying guns, right?
KODJAK: Yeah. There are certainly these laws on the books. Clearly, Kelley was able to get a gun anyway. His domestic violence conviction was never listed in the national criminal investigator database. And that's an official - an official at the Pentagon told NPR's Tom Bowman that this mistake meant Kelley wasn't flagged as part of his background check to be ineligible to buy a firearm. So the laws can be effective, but Webster said they have some pretty big holes.
WEBSTER: The most glaring one is that in our federal law and in many state laws dating partners are not covered.
KODJAK: And that's known as the girlfriend loophole. He says a lot of couples, even in abusive relationships, stay together a long time and never get married. So unmarried women are at even higher risk and their abusers aren't going to make it onto any database to prevent them from buying a weapon.
GREENE: OK. So this link is pretty clear. We know that domestic offenders may be more likely to commit mass shootings. Are there other signs to help predict who might become more violent?
KODJAK: Well, so obviously the people in the most danger are intimate partners of domestic offenders. And Webster says mass shootings are so rare that it's really hard to develop a strong pattern. But he did say there are few signs that authorities could look out for if they want to try to flag certain people. Here's what he says.
WEBSTER: Individuals who are amassing a number of weapons and a large amount of ammo, that obviously is a red flag. Individuals whose violence generally extends beyond the family relationship also would be an indicator of greater danger.
GREENE: But I just think about the massive attack in Las Vegas at that concert. The shooter amassed this huge number of weapons. I mean, police found them in that hotel room. But beyond that, we don't know anything about him. I mean, no reports of domestic trouble, no history of violence that we're aware of - a mystery.
KODJAK: Yeah. And that - you know, that's really the issue. Webster points out that trying to predict who'll become violent isn't an exact science, and especially in these mass shootings, there are perpetrators that fit some patterns, but there's no perfect profile of a person who's going to take a gun and kill a large number of people.
GREENE: All right, talking there to NPR health policy correspondent Alison Kodjak in our studio. Alison, thanks.
KODJAK: Thanks, David. Transcript provided by NPR, Copyright NPR.