In a prayer service in Newtown, Conn. on Sunday, President Obama called for change.

“We can’t tolerate this anymore. These tragedies must end. And to end them, we must change.”

Authorities say 20-year old Adam Lanza, was heavily armed when he forced his way into Sandy Hook Elementary School Friday morning – brandishing two semi-automatic handguns and an AR-15 style assault rifle.

The weapons belonged to Lanza’s mother, who purchased them legally. On NBC’s Meet the Press, Senator Dianne Feinstein said that’s a problem.

“I'm going to introduce the bill in the senate and the same bill will be introduced in the house. A bill to ban assault weapons,” Feinstein said.

Feinstein helped champion the Assault Weapons Ban, which President Clinton signed into law in 1994. But Congress allowed the ban to expire in 2004 and efforts to renew it have gone nowhere. Feinstein says Sandy Hook changed that.

“I think America is ready. They're going to have an opportunity with this bill. I'm going to ask and spend my time and create a committee across this nation to support it," Feinstein said.

But on Fox News Sunday, Texas congressman Louie Gohmert argued that things may have turned out different if the school principal had a gun.

“So when she heard gunfire she pulls it out, and she didn’t have to lunge heroically with nothing in her hands but she takes him out, takes his head off before he can kill those precious kids.”

That’s one school of thought. Meanwhile, the FBI reports that Americans bought a record 2 million firearms in November – before anyone was talking about gun control.

In an interview with Emily Rooney on Monday, David Hemenway, director of the Harvard Injury Control Research Center, said that there’s overwhelming evidence that where there are more guns, there are more deaths.

“A child in the United States is 13 times more likely to be murdered with a gun than a child in other developed countries like Spain. The other thing is that we have so many more guns and the weakest gun control laws,” said Hemenway.

Hemenway has a new approach to tackling the gun debate by looking at social issues and creating an awareness campaign.

"One law that we need is a universal background check.... We make it really easy for guns to get into the wrong hands. We make it really easy for gun traffickers to traffick guns. There are lots of minor things we can do," said Hemenway. "What we know is that in states where it's harder to get a gun, there's less gun violence."

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