Of more than 35,000 intimate partner violence incidents reported to the Philadelphia Police Department in one year, nearly a quarter involved a weapon, according to a new study from Susan B. Sorenson, a professor of social policy in the School of Social Policy & Practice and director of Penn’s Evelyn Jacobs Ortner Center on Family Violence. Of the 1,800 events where external weapons came into play—knives or bats, for example—nearly one-third were guns.

Moreover, Sorenson found that an abuser having a firearm, even if not fired, increased intimidation significantly.

“Women are less likely to be injured when a gun is used, but they’re far more likely to be frightened,” she says. Her findings were published in the Journal of Women’s Health.

Sorenson, whose research looks not only at homicides from intimate partner violence, but other effects as well, aimed to estimate just how frequently each weapon type appeared in such crimes.

The Philadelphia police gave her access to an entire year of department-mandated paperwork on 911 calls related to domestic violence, regardless of whether an arrest took place. The reports included information about first responders’ actions, a body map where officers could document victim injuries, and a section to describe what officers learned at the scene.

“The police department in Philadelphia has detailed information on all of its domestic violence calls, which is not common across the country,” she says.

Study findings offer a broad picture of weapon use in intimate partner violence. However, because the work assessed only incidents involving police, unlike the National Crime Victimization Survey, which includes any such incident regardless of whether police were summoned, Sorenson says there is unquestionably more firearm use than reported.  

She says this information can better prepare those who see victims soon after these crimes, such as health care professionals and police officers, who can ask about a gun. It can also affect policy decisions at the local, state, and federal level.

“We know that abusers and guns are a bad combination. And we have some good policies, such as the Violence Against Women Act, in place,” Sorenson says. “These make the purchase and possession of guns illegal by those against whom there was a domestic violence misdemeanor or restraining order.”

Evaluations of these laws rarely occur, so it’s unclear how well the laws get implemented and enforced. Plus, there’s the boyfriend loophole: In federal laws, keeping guns away from abusers applies only to those who had been married, had a child together, or had lived together, Sorenson explains.

“That [often] leaves out current or former boyfriends,” she says. “But boyfriends are as lethal as husbands.”

For this reason, Sorenson is actively working to analyze data from the Philadelphia police about this subject. She says it’s important to shift attention on the topic to pay attention to the lives—not just deaths—of abuse victims.