— -- On the heels of the deadliest gun massacre in modern U.S. history, Republicans and Democrats alike have decried the killings and offered supportive words to the hundreds of victims in Las Vegas.
With every major mass shooting, from Sandy Hook in sleepy Newtown, Connecticut, to Pulse nightclub in Orlando, come pleas from the public for officials to do something, anything, to address the scourge of gun violence in this country.
On this case, politicians from both sides of the aisle, with the support of the NRA, have indicated they may be open to a conversation about common sense gun restrictions, including restricting "bump stocks," devices designed to allow semi-automatic rifles to function like automatic weapons.
But perhaps part of the reason Congress hasn't fully addressed the rising tide of shootings is that the federal government lacks basic research into which solutions work best.
Dickey: Why the feds don't research gun violence
Passed in 1997 with the strong backing of the NRA, the so-called "Dickey Amendment" effectively bars the national Center for Disease Control and Prevention (CDC) from studying firearm violence -- an epidemic the American Medical Association has since dubbed "a public health crisis."
The amendment, which was first tucked into an appropriations bill signed into law by President Bill Clinton, stipulates that "none of the funds made available for injury prevention and control at the Centers for Disease Control and Prevention may be used to advocate or promote gun control." A similar provision was included in the Appropriations Act of 2012.
Named for Republican Rep. Jay Dickey of Arkansas, a self-proclaimed "point man for the NRA" on The Hill -- the Dickey amendment does not explicitly ban CDC research on gun violence. But along with the gun control line came a $2.6 million budget cut -- the exact amount that the agency had spent on firearm research the year prior -- and a quiet wariness.
As one doctor put it, "Precisely what was or was not permitted under the clause was unclear ... but no federal employee was willing to risk his or her career or the agency's funding to find out."
Critics argue that the government should not try to limit the collection of scientific information, which is by nature apolitical.
"Facts are facts," Amalia Corby, the American Psychological Association's senior legislative and federal affairs officer, told ABC News. "Public health researchers do not have a vested interest in the outcome."
Besides, experts say, non-partisan research could uncover a plethora of suggestions to help stem the tide of violence -- education strategies, guns storage solutions, etc. -- that don't include limiting access to guns.
"Violence prevention researchers are invested in less violence, not fewer guns," Corby said. "Their end game is not to take away guns."
Though President Obama formally directed the CDC to "the causes of gun violence and the ways to prevent it" shortly after the Newtown mass-murder in 2012, the chilling effect had already taken hold, and the CDC has consistently declined to allocate money to study the issue.
In fact, to this day, CDC policy states the agency "interprets" the language as a prohibition on using CDC funds to research gun issues that would be used in legislative arguments "intended to restrict or control the purchase or use of firearms."
Thus, researchers remain "afraid to even delve into that area of research because they're afraid of having their funding pulled," Corby said.
More than a decade after Dickey passed, Congressman Dickey himself came come to regret the law he had helped push.
"Firearm injuries will continue to claim far too many lives at home, at school, at work and at the movies until we start asking and answering the hard questions," he wrote in a Washington Post op-ed shortly after the Aurora, Colorado movie theater shooting that killed 12 in July 2012. "Scientific research should be conducted into preventing firearm injuries."
"I wish I had not been so reactionary," Dickey told ABC years later.
The congressman, who remained a staunch supporter of the Second Amendment until his death in April, said he once worried that the CDC's "agenda" was to take away guns. But he later joined forces with Mark Rosenberg, the former director of the CDC's gun research center, to promote academic inquiry into guns.
"Scientific research... it's our responsibility," Dickey explained. "It's silly for us to watch this nonsense take place, without doing something."
Why the ATF can't track guns electronically
Laws govern not only the tracking of gun violence statistics, but tracking of the firearms themselves too.
The Tiahrt Amendment, first sponsored by Kansas Republican Rep. Todd Tiahrt and recently reauthorized as part of another appropriations bill, prohibits the Bureau of Alcohol, Tobacco and Firearms (ATF) from maintaining a searchable database. Instead, officers attempting to trace a gun used in the commission of a crime must use a card catalog and phone system to track the weapon.
Often, officers find themselves forced to comb through boxes and boxes of paper records, many of them barely legible, by hand. The antiquated system -- which stretches the average processing time from hours to days -- cost taxpayers around $60 million over the course of 12 years, the ATF Tracing Center estimates.
Though proponents say the law prevents ATF overreach and protects the second amendment by barring a gun "registry," critics claim that Tiahrt has "unduly hampered" the agency from enforcing the law, according to the non-partisan Congressional Research Service.
By the numbers
According to the Gun Violence Archive, a nonprofit that tracks firearm violence across the country, there have been 275 mass shooter incidents -- defined as a shooting involving four or more victims injured or killed -- to date in 2017.
In the same time period, more than 11,700 people, including minors, died by gunshot, whether intentional or accidental, and nearly 24,000 were injured.
The CDC -- which notes that the Dickey amendment does not prohibit public health data collection -- says that firearm-related injuries are among the five leading causes of death for people ages 1-64 in the United States.
The NRA did not respond to ABC News' repeated requests for comment. The organization spent more than $3.2 million on lobbying in the first half of 2017, according to the Senate Office of Public Records' lobbying database.
ABC News' Lauren Pearle and Geneva Sands contributed to this report.