Many years later, the National Institutes of Health funded a similar study that triggered the same lightning-bolt response.

In 2009, the NIH study concluded that a person carrying a gun was nearly 4.5 times more likely to be shot in an assault than someone who is unarmed.

Two years later, Congress added the same restrictive language it had imposed on the CDC to all agencies of the Department of Health and Human Services, including the NIH.

Today, the NRA maintains its position that government research into gun violence is not necessary.

"What works to reduce gun violence is to make sure that criminals are prosecuted and those who have been found to be a danger to themselves or others don't have access to firearms," the NRA's Arulanandam said, "not to carry out more studies."

Unanswered questions

So why are government studies on gun violence necessary?

Rosenberg, who left the CDC in 1999, explained that many of the questions that his group was seeking to answer remain open.

For example, he said, it's not clear whether registering and licensing firearms lowers gun violence; whether allowing people to carry concealed weapons increases or lowers the risk of gun deaths; or how letting people carry weapons in places such as shopping malls or schools or bars or parks affects the number of deaths.

"These are very big questions that we need to know the answer to," said Rosenberg, who is now president and CEO of The Task Force for Global Health.

There are other private agencies and even partly federally funded programs that have researched these issues.

But none was as far-reaching as what Rosenberg's program did in the 1990s.

The CDC's website still keeps track of the toll of gun violence -- or, as the CDC sometimes calls it, "lethal means." Yet, the federal agency does little of the epidemiological research it once did that might offer guidance to lawmakers.

Now that gun violence has been thrust into the forefront of issues on Capitol Hill after last month's mass shooting at a Newtown, Connecticut, elementary school, the focus has turned to the medical community's role in the debate.

Last week, The Washington Post reported on a little-known provision added to the 2010 Affordable Care Act -- better known as Obamacare -- limiting what doctors can ask their patients about firearms in the home.

While the provision doesn't forbid doctors from asking about guns, it prohibits health care workers from collecting that information, documenting it and using it for research.

A similar law in Florida went a step further and would actually penalize doctors if they ask their patients about whether they own a gun, in most cases. A federal judge overturned the law, but Gov. Rick Scott has vowed to appeal.

Gun-rights advocates, including the NRA, have raised concerns about tracking this data, including the possibility that acknowledging legal gun ownership could bring higher insurance premiums.

With these restrictions and the revived gun debate, doctors should become active participants in the discussion about gun violence and gun policy in this country, according to the American College of Physicians.

After all, the group said in a recent publication, physicians take a stand on other public health issues, such as smoking, air pollution, drunk driving and vaccinations.

Examining gun violence isn't a political issue to most physicians, one Florida doctor said.

"Physicians basically want two things: They want continued research so we can find out what is happening along the lines of firearms and health care," Dr. Carolyn McClanahan told CNN's Sanjay Gupta. "And the second thing, though, is we want to provide basic gun education. Studies have shown if you ask parents, especially pediatricians ask parents, 'Do you keep your gun locked, unloaded, keep the ammunition separate from the gun?' that decreases the chance of a death from a firearm."

Where things stand now

When Adam Lanza unleashed a hail of bullets inside an elementary school on December 14, ending the lives of 20 young children and six staff members, the debate over America's gun laws reopened.

Days later, Obama announced that a task force led by Vice President Joe Biden would create "real reforms right now."