The investigation into the deadly shooting at Washington’s Navy Yard Monday is sparking calls for new gun control measures. Authorities say, earlier this month, Aaron Alexis purchased a shotgun he used to kill 12 people at the naval command building.
Federal law enforcement investigators continued to gather evidence at Washington's Navy Yard.
Authorities are still unable to say what caused Aaron Alexis to gun down 12 people in Monday's rampage before police shot and killed him. Witnesses say Alexis, a former Navy reservist and contract worker, entered the building with a shotgun, and a short time later began firing. John Weaver watched as the suspect killed his co-worker.
"I popped my head up, and I saw him pointing his gun at my friend, and he shot her," said Weaver.
The latest shooting has renewed the debate over stricter gun control. Many gun owners oppose stricter laws. President Barack Obama is again urging lawmakers to enact new legislation.
"The fact that we do not have a firm enough background check system [for purchasing firearms] is something that makes us more vulnerable to these kinds of mass shootings," said President Obama.
There were 78 mass public shootings in the U.S. over the past three decades, resulting in 547 deaths, according to a study released in March by the Congressional Research Service.
On Capitol Hill, members of Congress were joined by families of shooting victims, including relatives of some of the 26 people gunned down at an elementary school in Connecticut last year.
Senator Chris Murphy:
"Something is broken with our democracy when 90 percent of Americans think the people should get a background check before they buy a gun and we cannot get a vote in the United States Congress," said Murphy.
Earlier this year, gun control legislation died in the Senate when some Democrats and many Republicans opposed new restrictions on firearms purchases.
Steve Billet is a political science professor at George Washington University.
"I think we’re numb, quite frankly, when it comes to the gun control issues. I think there are a lot of people who simply reconciled themselves to the fact that these are isolated incidents that we have to deal with from time to time and that’s that," said Billet.
Gun rights advocates like the National Rifle Association did not issue a statement after the Navy Yard shooting. But in the past they have fought against efforts to infringe on Americans' right to own guns.
The NRA is powerful. Its members and gun supporters in Colorado celebrated after voters ousted two state senators who supported modest gun control measures. Connecticut Congresswomen Elizabeth Esty is ready to fight back.
"This cannot become the new normal. This is unacceptable," said Esty.
Despite calls for stricter gun control, analysts say there's still not enough support in Congress to pass gun legislation this year.