Shooting unfolded hours after doctors pushed to lift gun violence research ban

Hours before a deadly mass shooting unfolded in San Bernardino, doctors delivered a petition to Congress, calling on lawmakers to lift a funding ban on gun violence research at the Centers for Disease Control and Prevention.

Dr. Alice Chen, executive director of the advocacy group Doctors for America, called gun violence a "public health problem" that kills nearly 90 Americans each day.

"Physicians believe it's time to lift this effective ban and fund the research needed to save lives," Chen said in the petition signed by more than 2,000 physicians and backed some Democratic lawmakers. "We urge Congress to put patients over politics to help find solutions to our nation's gun violence crisis."

Hours later, the gun violence crisis added another dark chapter as two suspects unleashed fire suspects at a social services center in San Bernardino, killing 14 people and wounding more than a dozen others.

Since 1996, Congress has barred the CDC from using federal funding to "advocate or promote gun control." That language, which emerged out of pressure from the National Rifle Association (NRA), effectively halted CDC's efforts to study gun violence because of concerns that it would risk losing even more funding.

Experts who study gun violence say without CDC research, many questions about gun violence remain unanswered.

"While we do have research showing the benefits of some laws such as handgun purchaser licensing with background checks for all handgun sales, there are relatively few studies of good scientific rigor that can tell us whether changes associated with gun laws are experienced by the individuals targeted by the law," Daniel Webster, director of the Johns Hopkins Center for Gun Policy and Research, told CBS News.

Lawmakers who backed the petition echoed that sentiment.

"Regardless of where we stand in the debate over gun violence, we should all be able to agree that this debate should be informed by objective data and robust scientific research," said Rep. David Price.

After the shooting, Price told the Washington Post that the timing of the petition was "ironic."

"It certain does underscore what we were saying earlier today about the scourge of gun violence, which has become such a feature of our daily lives," he told the Post.