Sandy Hook
Parents of Sandy Hook victim Grace McDonnell grapple with their grief after 20-year-old Adam Lanza fatally shot 20 children in the Connecticut school in 2012Reuters

The US federal government passed an amendment to an appropriations measure 20 years ago essentially barring the US Centers for Disease Control and Prevention (CDC) from using funds for gun research because findings might be used to "advocate or promote gun control." But 141 American medical associations are now calling on Congress to lift the ban and fund "critical" CDC research into gun violence, which kills 30,000 Americans a year.

"The medical and public health communities continue to believe gun violence, which claims an average of 91 American lives daily, is a serious public health threat that must be handled with urgency," Dr Alice Chen, executive director of the umbrella group Doctors for America, said in a statement.

"Congress must lift the barrier to research that has persisted for nearly 20 years and fund the work that we need to save lives."

The letter calling for restoration of funding into gun research was sent to four senior members of the House and Senate Appropriations Committees. Organisations that have signed the letter include most of the top health groups in the nation, including the American Medical Association, the American Academy of Pediatrics, the American Association for the Advancement of Science and several research universities.

"Medical professionals and our communities work to address the devastating and long-lasting physical and emotional effects of gun violence on victims, their families and their friends, but are hampered by the insufficient body of evidence-based research to use to point communities toward proven gun violence prevention programs and policies," the letter reads.

"A central part of preventing future tragedies is through conducting rigorous scientific research as this has been a proven successful approach in reducing deaths due to other injuries."

Funding for gun violence research dried up in 1996 after the so-called Dickey Amendment – named after Arkansas GOP Congressman Jay Dickey – was tacked on to an appropriations bill to block funds from research that might be used to bolster arguments for gun control.

Dickey now regrets pushing the amendment and wants research into gun violence. "I just regret it. I just regret that we didn't maintain the commitment to funding science and research," Dickey told The Trace in an interview in December 2015.

Just a day before the mass terrorist shootings in San Bernardino, California, Dickey published a letter to Congress, noting that "research could have been continued on gun violence without infringing on the rights of gun owners; doing nothing is no longer an acceptable solution."

Congressional leaders are yet to respond to the letter from the medical associations.