Sitora Yusufiy, the first wife of Omar Mateen, who murdered forty-nine at an Orlando night club, has said that he abused her when they were married. PHOTOGRAPH BY KATHRYN SCOTT OSLER / THE DENVER POST VIA GETTY

Soon after Sunday’s massacre in Orlando, Omar Mateen’s first wife, Sitora Yusufiy, told reporters that when she was briefly married to him, seven years ago, he made a practice of abusing her. “He would just come home and start beating me up because the laundry wasn’t finished or something like that,” Yusufiy said. The couple had met online, and she had moved to Florida to marry him, but the beatings began almost immediately, and he was soon preventing her from speaking to her family, “keeping me hostage from them,” she said. In the end, her family had to rescue her, physically pulling her out of his arms, she said.

In the toxic brew of background details about Mateen, this might not seem like the most salient. Surely more relevant was the fact that he felt some sort of identification with terrorists and with ISIS. It mattered a great deal that he had targeted a gay night club and, in ways still to be illuminated, that it was one he himself had reportedly visited. It mattered that his father claimed that Mateen had been enraged by the sight of two men kissing but that, as it emerged this week, he had apparently made use of an online dating app for gay men. And, of course, because this is the United States, where a third of all the mass shootings in the world take place, it mattered, perhaps most of all, that he could easily obtain a weapon for which no civilian has any justifiable need, one designed to kill and maim the most people in the shortest period of time.

In fact, though, there is a connection between domestic violence and mass shootings, and in acknowledging that connection there is some hope for helping to prevent both. A recent analysis of mass shootings, conducted by the research-and-advocacy group Everytown for Gun Safety, found the link to domestic violence “noteworthy.” Using the F.B.I.’s definition of mass shootings as incidents in which four or more people are murdered by guns, the Everytown researchers were able to document a hundred and thirty-three such shootings between January, 2009, and July, 2015. They found that “in at least 76 of the cases (57%), the shooter killed a current or former spouse or intimate partner or other family member, and in at least 21 incidents the shooter had a prior domestic violence charge.”

The lethal intersection of firearms and intimate-partner violence is actually one of the few gun-safety matters that Congress has acted on. In 1996, it adopted the Lautenberg Amendment, which bans people who have been convicted of domestic-violence misdemeanors, or who are subject to restraining orders, from owning firearms. This was sound and compassionate legislation. Guns are the most common method, by far, for killing intimate partners. Not surprisingly, the presence of a firearm in the home makes it much more likely that a woman in an abusive relationship will end up dead. And there is evidence that restrictions of the kind the Lautenberg Amendment and some state legislatures have enacted truly help. According to researchers at the Johns Hopkins Bloomberg School of Public Health, “laws restricting firearm access for batterers subject to restraining orders are associated with a 19% reduction in rates of intimate homicide.”

Unfortunately, the federal law and similar state laws are spottily enforced. These regulations are only effective if states put in place a screening process for potential gun buyers, to see if they have restraining orders against them—and many states have not. In those cases, there is nothing to stop domestic abusers from buying, say, semiautomatic assault rifles, other than their willingness to self-report. The same applies to turning in guns they already own. Some states have laws that allow police to seize firearms when responding to domestic-violence incidents, but most do not. This term, the Supreme Court heard a challenge to Maine’s version of this law from two men who said that their constitutional rights were violated when they had to give up guns for misdemeanor domestic-violence convictions. (One of the men was discovered still to be in possession of a firearm when a stranger reported him for shooting a bald eagle—a federal crime.) The case got some attention, in February, mainly because it spurred Justice Clarence Thomas to ask a question from the bench for the first time in ten years. But when the Court issues its opinion in the case (it is expected this month) it will have real implications for people at risk from intimate partners, and for gun safety more generally. Meanwhile, municipal nuisance ordinances across the country allow landlords to evict tenants who have frequently called 911—a punishment that falls particularly hard on victims of domestic violence.

It’s time to recognize domestic violence and misogynistic anger for the warning signs they often are. Seung-Hui Cho, the perpetrator of the killings at Virginia Tech—until Orlando the deadliest shooting by a single gunman in U.S. history—had previously been charged with stalking female students. One of the two Boston Marathon bombers, Tamerlan Tsarnaev, had been arrested, at his apartment, for domestic assault and battery of a woman. Terror, it seems, sometimes begins at home.