Minnesota Gov. Tim Walz’s son, Gus, witnessed a shooting last year at a St. Paul recreation center in which a teenager was shot in the head — something the Democratic vice-presidential nominee said as he argued for policies to reduce gun violence at Tuesday night’s debate.

During a line of questioning about gun violence — the leading cause of death for American children and teens — Walz said, “Look, I got a 17-year-old, and he witnessed a shooting at a community center playing volleyball. Those things don’t leave you.”

He continued, “As a member of Congress, I sat in my office surrounded by dozens of the Sandy Hook parents, and they were looking at my 7-year-old’s picture on the wall. Their 7-year-olds were dead, and they were asking us to do something.”

Gus Walz, who was not involved in the January 2023 shooting, was at the rec center when an employee shot a 16-year-old boy after an argument, the Harris-Walz campaign confirmed to The Washington Post. The boy survived but still suffers from his injuries, according to Minnesota Public Radio.

Walz also talked about the incident during a recent rally in Grand Rapids, Mich., where he discussed his stance on gun control and said, “my own son was in a location where someone was shot in the head.”

Gun violence, an issue that roars into the public debate with every mass shooting, has not emerged as a central campaign issue — but it affects Americans daily, with tens of thousands of people dying from gun-related deaths per year. There have been 23 mass killings using firearms in 2024, according to a Post count. There had been 33 as of Oct. 1 last year, and 2023 saw 39 in total.

In 2022, more than 2,500 children and teens died by firearm, with scores more witnessing violence, according to the Johns Hopkins Center for Gun Violence Solutions.

The candidates on both tickets are gun owners. Republican presidential nominee Donald Trump, who has been backed by the National Rifle Association, has pledged to support gun rights and to undo regulations advanced by the Biden administration. Democratic presidential nominee Kamala Harris, who has said she wants to make communities “safer from gun violence,” supports banning assault weapons, expanding background checks and temporarily removing weapons from people deemed to pose an immediate danger.

Walz’s disclosure during the debate prompted a direct response from his opponent, Sen. JD Vance (R-Ohio). The Republican vice-presidential nominee, who drew criticism last month for referring to school shootings as a bleak “fact of life,” on Tuesday called gun violence a “terrible epidemic.”

“I didn’t know that your 17-year-old witnessed a shooting, and I’m sorry about that,” Vance said after Walz was done speaking. “Christ have mercy. It is awful.”

“I appreciate it,” Walz responded.

The nominees offered differing responses to the question of how to reduce gun violence and school shootings. Vance suggested that schools be physically fortified by making “stronger” doors and windows and assigning more resource officers, a common conservative recommendation for tackling gun violence. He called for “common-sense, bipartisan solutions,” a phrase gun-control advocates typically use, without endorsing any policies beyond those to increase school security.

“We know, unfortunately, that a lot of kids are going to experience this terrible epidemic of gun violence. And of course, our hearts go out to the families that are affected by this terrible stuff,” Vance said, adding: “We’ve got to make our schools safer.”

He also said that gun violence in major cities should be curbed through arrests by law enforcement, and suggested that mental health issues, such as depression and anxiety, are factors in shootings — something critics say unfairly stigmatizes people with mental illness and ignores research that shows that violence is more likely when firearms are present.

Walz advocated for red-flag laws, background checks and better gun-violence data collection and research — proposals backed by gun-control advocacy groups. Such legislation has been opposed by Republicans, including Vance, who say the federal government would overstep in passing such measures.

Walz sought to portray such proposals as compatible with the Second Amendment and cast skepticism on Vance’s policy stance, saying, “Do you want your schools hardened to look like a fort?” Walz said a Democratic administration would not infringe on voters’ rights to bear arms but also said that “our first responsibility is to our kids to figure this out.”

“These are things that shouldn’t be that difficult,” he said. “You can still keep your firearms and we can make a difference.”

After Vance spoke, Walz noted that they were in agreement that shootings were “abhorrent.”

“I do think that this is a good start to the conversation,” Walz said.