American flags were still at half-staff in some places honoring the Marines who were fatally shot in Chattanooga nearly two weeks ago.
"We need to do a better job on the background checks," said Richard Martinez.
From Lafayette to Chattanooga to Charleston, the tragedies hit close to home for Martinez.
"I flashback to what it was like for us that night and I know what those people are going through," he said.
Martinez's 20-year-old son, Christopher Ross Michaels-Martinez, was fatally shot last year outside a California deli.
"The shooter had over 500 rounds, over 500 bullets left at the time he died," said Martinez. "He had three handguns, he fired 70 rounds, he shot and killed three people that evening."
The shooter reportedly took his own life.
Martinez spent Tuesday morning on Capitol Hill sharing his story in hopes that lawmakers will back a mandatory background check for people purchasing firearms.
"I'm here with Everytown [for Gun Safety] and others to demand that Congress take a vote on background checks," said Martinez.
Everytown for Gun Safety is an advocacy group that supports laws that will prevent gun violence.
When asked about critics who say background checks are not a solution, Everytown for Gun Safety spokesperson Stacey Radnor said, "It is a solution. Research shows us that background checks on gun sales are the most effective way to save lives."
A background check would not have changed the outcome in Lucia McBath's case. Her 17-year-old son, Jordan Davis, was fatally shot three years ago in Florida over loud music.
His killer legally obtained a gun.
"It's too late for Jordan, but there's still a massive gun culture with a lot of problems and loopholes in our gun laws and those are the ones I'm trying to save," said McBath.
Sen.Tim Kaine (D-Va.) and a dozen of his Senate colleagues urged gun dealers to stop selling firearms to people who do not first pass a background check.
We attempted to contact the National Rifle Association for reaction, but there was no response.