Devin Patrick Kelley, 26, opened fire inside a Texas Church, killing at least 26 people.
As the latest US shooting sparked fresh debate over gun control, a TV star has moved to shut down a popular line of argument against stricter laws.
Andy Richter, Conan O'Brien's sidekick on his talk show, took to Twitter to debunk the claim often used by those who do not believe gun laws need to be tightened.
Chicago has some of the strictest laws in the country but has struggled to combat gun violence. It's a fact many pro-gun activists say proves that increasing firearm legislation won't stop killers like Devin Kelley, who shot dead 26 people at a Texas church.
Donald Trump has used the example more than once.
White House press secretary Sarah Huckabee Sanders was asked after last month's Las Vegas massacre, in which 58 were shot dead, whether the President's views on gun control had changed. "If you look to Chicago, where you had over 4000 victims of gun-related crimes last year, they have the strictest gun laws in the country," she said. "That certainly hasn't helped there."
Trump made the same point a year earlier, in his final presidential debate with Hillary Clinton. "In Chicago, which has the toughest gun laws in the United States, probably you could say by far, they have more gun violence than any other city," he said. "So we have the toughest laws, and you have tremendous gun violence."
But a recent report released by the third-most populous city in the United States gives a good indication of why.
The state of Illinois, in which Chicago is situated, may have comparatively strict gun laws - but it is surrounded by states with very lax ones, which allow illegal firearms flow across the border.
"It is the very states with the least restrictive gun laws that are the sources of the guns coming into Chicago and being used to commit crimes," reads the Gun Trace 2017 report. "The Chicago Police Department has consistently traced close to 60 per cent of its crime guns to other states.
Community members at a candlelight vigil for their slaughtered neighbours in Sutherland Springs, Texas. Photo / Ap
"States with lax gun laws like Indiana and Mississippi are a primary target for gang members and their gun trafficker source buyers.
"Illinois can and must do better to reduce the flow of guns from in-state [federally licensed firearms] dealers. But even with this necessary step forward to regulate in-state firearm sales, Chicago remains uniquely vulnerable to interstate firearms trafficking due to surrounding states with weak regulations over the primary and secondary gun sale markets, including Indiana, Wisconsin, and Kentucky.
"Not just Chicago, but the nation, needs a national response to meaningfully deter illegal gun trafficking and the subsequent gun violence that follows in its wake."
Nearly 60 per cent of Chicago's guns come from outside the state. Photo / Chicago Police Department
Richter's Twitter thread, which succinctly lays out this information, has already had almost 4000 retweets.
He notes that the gun lobby has made it near impossible to track and investigate the sales of illegal guns like those that flood Chicago's streets.
The comedian adds that the only reason there isn't a national gun database, as there is for cars, is because of "paranoid bs that keep(s) gun makers rich." He said it was time there were careful records kept centrally for all sales.
"Might be able to take it if the ppl spouting it had a drop of concern for the ppl of Chicago rather than puking up gun cult disinformation that protects their f***ing hobby.
"USA will always have guns, but more control is needed.
"Americans are being slaughtered in churches, concerts, stores and schools.
"F*** your hobby. Grow up and think of someone else."
