HARTFORD (AP) — The 2012 massacre at Sandy Hook Elementary School has become an emotional issue in the final days of Connecticut's close race for governor.

Democrats gathered at the state Capitol Monday to warn that electing Republican Bob Stefanowski could risk the wide-ranging gun control measures passed by the General Assembly following the deadly Newtown mass shooting. They also claim electing someone backed by the NRA as Connecticut's next governor would send the wrong message to the nation and destroy momentum for federal gun safety legislation.

"Why on earth would Connecticut, a state that has seen epic-scale mass-gun tragedy, choose to elect a governor who is going to put AR-15s back on the streets of this state,?" asked Democratic U.S. Sen. Chris Murphy, who is seeking re-election in November.

Stefanowski, meanwhile, has pushed back, accusing Democratic gubernatorial candidate Ned Lamont of trying to exploit tragedy for political purposes. His campaign last week distributed a tweet to reporters from the teenage brother of a Sandy Hook victim who took issue with a TV ad Lamont is running. It focuses on the Sandy Hook legislation and features Erica Lafferty-Garbatini, the daughter of school's late principal Dawn Lafferty-Hochsprung. She claims Stefanowski would "go back to the laws that allowed my mom to be murdered."

JT Lewis, whose brother Jesse was killed, wrote a letter to Lamont, saying he crossed the line by "preposterously accusing your opponent of supporting murder in an attempt to win an election." He called on Lamont to pull the ad.

"Using our lost loved ones as a political weapon is shameful and disrespectful to the memories of our families," Lewis wrote in his letter to the Democratic businessman.

Lamont defended the ad Monday, saying Lafferty-Garbatini "came to us" because "she really wanted to speak out" in support of protecting Connecticut's expanded gun control laws.

"I'm proud that that is up there," he said of the ad. "I'm proud that we're talking about the real differences between Bob Stefanowski and I in terms of where we go forward."

Lamont has called for closing any loopholes in existing state gun laws, barring untraceable 3-D-printed guns and limiting the number of guns that can be purchased at once.

Lewis has advocated for additional safety measures at schools and more mental health care. Stefanowski has taken a similar stance, calling for armed resource officers at every school, single entry points and other design elements to protect students. He has also called for restoring state funds cut for mental health services and reversing reductions in Connecticut's state trooper ranks.

"For Bob, the safety of our children is always our top priority," said Stefanowski's campaign spokesman, Kendall Marr.

Marr did not respond directly to the Democrats' accusations that Stefanowski would try to overturn it. The Democrats on Monday released a video of Stefanowski from earlier this year, where the Republican tells a group he would veto any legislation that would make the legislation tougher on gun owners.

"Bob believes we need to strike the appropriate balance between protecting the rights of law-abiding gun owners and efforts to keep guns out of the hands of people that should not have them," Marr said in a written statement.

On a bipartisan vote in 2013, the Connecticut General Assembly passed the wide-ranging package of gun control measures following the Sandy Hook mass shooting, which left 26 people, including 20, children dead. The list of changes included an expanded assault weapons ban, a ban on large-capacity magazines and armor-piercing bullets, expanded background checks and other measures. While some Connecticut gun rights supporters remain angered by the legislation, which they claim is an overreach, there has been no major effort in the legislature to overturn the law since its passage.

Petitioning independent candidate Oz Griebel, whose running mate Monte Frank is a former Democrat from Newtown who has advocated for stronger gun laws, has said he supports the legislation passed in the wake of the Sandy Hook mass shooting.