PHILADELPHIA - We're hearing more calls for action on gun control after a string of mass shootings across the country over the weekend.

That includes one in Philadelphia that left three people dead and 11 injured. Philadelphia District Attorney Larry Krasner was supposed to have a news conference Monday announcing a conviction in the 2018 shooting death of Tyisha Timmons, but before he could talk about that, he had to address the latest shooting in his city, something he said could be prevented through stricter laws. Krasner had strong words for his elected representatives.

"Any legislator who is not willing to put the lives of innocent bystanders of women and children and young adults above their political future belongs out of office," said Krasner.

Pennsylvania has now seen 12 mass shootings so far this year, according to the Gun Violence Archive, but the state seems no closer to passing stricter laws. House Bill 770, which would ban assault rifles in the state, failed in the House last month, just one day after the Uvalde, Texas shooting, to the frustration of Allentown Rep. Peter Schweyer.

"We can't get our arms around something that is literally killing America's children on a daily and weekly basis. It is shameful. It is the great shame of our generation," said Schweyer.

But there may be movement on gun legislation in the U.S. Senate. Republican Pennsylvania Sen. Pat Toomey said on Face the Nation on Sunday that a bipartisan committee he's a part of is considering making changes to national background check laws.

"At least for commercial sales of firearms, there ought to be a background check. So sales at gun shows, sales that are advertised over the internet," said Sen. Toomey.

A change people like Krasner say would lead to fewer families mourning their loved ones. Families like the Timmons.

"I just, I miss my daughter, and she wasn't just my daughter. She was my friend, she was my best friend, and something that they took from me that I could never get back," said Timmons' mother, Lisa Timmons.

In his interview on Face the Nation, Sen. Toomey mentioned he had previously introduced bipartisan legislation with Democratic Sen. Joe Manchin to expand background checks in 2013, but it failed.

He's hopeful this time around there may be more political pressure to get it through.

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