A nearly two-decades-long ban on federal funding to study gun violence has been lifted, and a look at existing data shows the dangerous effects of easy access to firearms.

Dinyal New of Oakland, Calif. lost her 13-year-old son, Lee Weathersbee III, when he was shot walking out of a Boys & Girls Club on New Year’s Eve.

Just weeks after the teen was laid to rest, New lost another teenage son, Lamar Broussard, as perpetrators shot into a car occupied by Broussard and a friend in Oakland.

“I have no more kids,” New told the San Francisco Chronicle.

Each year in the U.S., an estimated 31,000 people die from firearms, according to the U.S. Centers for Disease Control and Prevention (CDC).

The news of her second son’s death reached the Oakland mother on the same day The Annals of Internal Medicine released a study on the incidence of gun violence in America.

While the findings are not surprising—that access to firearms is associated with a higher risk of suicide and being the victim of homicide—it comes after political pressure on agencies studying gun violence has eased.

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Researchers at the University of California, San Francisco (UCSF), performed a meta-analysis of 15 studies on gun access and gun violence.

The new analysis showed that greater firearm accessibility meant men were nearly four times more likely to commit suicide by firearm and women were almost three times more likely to be the victims of homicide.

Researchers added that about 75 percent of suicides and firearm-related homicides in which women are the victims occur at home.

“Since empirical data suggest that most victims of homicide know their assailants, the higher risk for women strongly indicates domestic violence,” Andrew Anglemyer, a U.S. Army veteran and data analytics expert in UCSF’s pharmacy and global health sciences programs, said in a release.

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The study excluded data from cases in which the death was ruled accidental. Researchers also adjusted for mental illness, arrest history, and other potential biases in the original studies they examined.

More than half the studies were conducted after a 1996 federal ban went into affect preventing the U.S. Department of Health and Human Services—the parent agency of the CDC—from funding research that could be seen as promoting gun control.

In the 1970s and 80s, the CDC tracked the impact of firearms on human deaths.

But when appropriating budget money for the 1997 fiscal year, lobbying from the National Rifle Association (NRA) and other Second Amendment groups ensured that the language of the funding bill clearly stated that “none of the funds made available for injury prevention and control at the [CDC] may be used to advocate or promote gun control.”

Following the Dec. 14, 2012, shooting at Sandy Hook Elementary School in Newtown, Conn. during which 20 children and six adults were killed, public outcry to curb mass shootings reached an all-time high.

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The research funding ban was challenged by many, including more than 100 scientists who wrote to Vice Pres. Joe Biden to ask for data-driven policy and the roll-out of the National Violent Death Reporting System in all 50 states.

Biden took the side of the scientists, speaking out against the lobbying power of the NRA.

“It bothers me that part of the interest group population out there is afraid of facts,” Biden said at the time. “Let the facts lead where they will, and let the research be done. That’s something that the president and I feel very strongly.”

Increased public pressure prompted Pres. Barack Obama to lift the gun research ban, making government money available to study the effects of firearm accessibility starting Jan. 1 this year.