Connecticut Sens. Chris MurphyChristopher (Chris) Scott MurphyMichigan Dem: Detroit-style pizza 'sweeping the nation' Overnight Cybersecurity: Senators want info on 'stingray' surveillance in DC | Bills to secure energy infrastructure advance | GOP lawmaker offers cyber deterrence bill Overnight Health Care: GOP pushes stiff work requirements for food stamps | Johnny Isakson opens up about family's tragic loss to opioids | Republicans refuse to back vulnerable Dem's opioids bill | Dems offer new public option plan MORE (D) and Richard Blumenthal (D) on Thursday said it was "shameful" that Congress hasn't passed new gun control legislation.

The two senators represent the state where 20 first graders were killed in a December 2012 shooting that led to a new fight over gun control measures in Washington.

“Every day, more and more people are lost to gun violence, and the need for common-sense anti-gun violence measures becomes more and more clear,” Murphy said Thursday. “It's shameful that Congress still refuses to listen to the overwhelming majority of the American people who support strengthening life saving federal background check laws.”

After the Sandy Hook Elementary School shooting in Newtown, Conn., in December 2012, the two senators have chided Congress for not passing any gun control reforms.

Shortly after the incident, the Senate came close to passing bipartisan legislation that would have expanded background checks for all gun sales, including those made online. But after the National Riffle Association strongly opposed the bill, it failed to overcome a 60-vote hurdle to advance the measure.

“Universal background checks should be common ground for both sides of the gun violence debate,” Blumenthal said. “Fifteen states enacted toughened gun laws in the wake of the Newtown tragedy, but our borders are porous, and states like Connecticut with responsible common-sense laws remain victim to the least common denominator — laws of neighboring states. Federal action is needed, and history is on our side.”

The senators’ remarks were prompted by the release of a study that found the repeal of Missouri’s background check law has resulted in nearly 60 more homicides a year — a 16 percent increase.

“This data clearly shows that weakening background checks laws leads to more guns getting into the wrong hands, too often with deadly results,” Murphy said.