Sen. Pat Toomey (R-Pa.) called for a law on background checks after two mass shootings on Sunday that shocked the nation. 

“While no law will end mass shootings entirely, it’s time for Congress to act to help keep our communities safer,” Toomey tweeted. “We should start by passing bipartisan proposals such as my legislation with Senator Joe Manchin to expand background checks to all commercial firearm sales.” 

Twenty people were killed and many wounded after a gunman with an assault rifle attacked a Walmart in El Paso, Texas, on Saturday, Aug. 3. 

Within hours, another mass shooting happened in Dayton, Ohio, where a gunman killed at least nine people and wounded more than two dozen before being taken down by police officers.

Earlier this year, the House passed a universal background check that would ban most person-to-person firearm transfers without a check, which aimed to close potential loopholes, according to The Hill.

“Toomey and Democratic Sen. Joe Manchin (W.Va.) first introduced their background check bill, which would expand background checks to include unlicensed gun-show dealers and online sales, in 2013,” the Hill reported.

Sen. Susan Collins (R-Maine) also supported the bill, saying in her latest tweet, “I have long supported closing loopholes in background checks to prevent the sale of firearms to criminals and individuals with serious mental illness.”

On Sunday Sen. Lindsey Graham (R-S.C.) said in his tweet that it “may not have mattered here, but Red Flag laws have proven to be effective in states that have them.”

Toomey agreed with him, saying “I also agree with Senator Lindsey Graham that we should pass a bipartisan “red flag” measure that enables families and law enforcement to obtain a court order to keep guns away from dangerous individuals.”