Earlier this week, the Senate unanimously passed legislation designating Pulse, a gay nightclub in Florida, a national memorial.
The suit said the employee Jacob Mace was able to buy a shotgun from the Maryland Walmart store where he worked.
Brandon Hole, 19, opened fire at a FedEx facility in Indianapolis on April 15, killing 8 people before taking his own life, authorities said.
Democratic leadership has reportedly been waiting to address gun control in the Senate in hopes of coming to a bipartisan agreement with the GOP.
In the majority of states, a person can obtain a firearm from a private seller, at gun shows and elsewhere, without undergoing a background check.
The law comes as President Joe Biden announced new gun control executive orders following several mass shootings.
Biden on Thursday announced six executive actions to address the "epidemic" of gun violence in the United States.
President Joe Biden made the comment about guns as he announced his executive actions targeting gun violence on Thursday.
"Today, we're taking steps to confront not just the gun crisis, but what is actually a public health crisis," Biden said Thursday.
The actions, which do not require approval from Congress, come in the wake of recent mass shootings and homicide spikes in US cities.
Graham made the same claim in 2019.
After the Boulder grocery store shooting this week, lawmakers say they are again looking at incremental changes.
"It has to be possible that people agree that these slaughters have to stop," Harris said as Republicans rejected calls for more gun control.
Cruz also ripped Democrats, alleging they play 'ridiculous theater' by proposing gun legislation like universal background checks after mass shootings.
The dual tragedies have again reinvigorated calls for federal gun control and activists have zeroed in on ditching the filibuster as a first step.
Kennedy suggested that the issue of gun violence is overblown, after mass shootings have killed 18 people in the country in the past week.
Obama's comments come after a gunman fatally shot 8 people in an Atlanta-area shooting this week.