It’s been 10 years since 20 students and six educators were killed at Sandy Hook Elementary School in Newtown. As family members grappled with grief, the shooting also spawned a political movement.

U.S. Sen. Chris Murphy (D-Conn.) said years of gun reform efforts culminated in the Bipartisan Safer Communities Act, which President Biden signed into law in June.

The new law enhances background checks, financially supports red flag laws and aims to crack down on gun trafficking. It also invests in mental health services and school safety.

Murphy said the Sandy Hook shooting was a “tipping point” that set off years of behind-the-scenes conversations on gun reform in Washington, D.C.

“What happened in Newtown changed the politics and the culture of this country,” Murphy said in an interview with Connecticut Public. “It set in motion a political movement determined to try to make sense of the nation’s gun laws. But it also set off the gun lobby in a pretty radical direction.”

Connecticut gun laws changed after Sandy Hook. Murphy says more needs to change. 

After Sandy Hook, Connecticut strengthened its assault weapons ban and required background checks for all firearm purchases. The Centers for Disease Control and Prevention notes that Connecticut has one of the lowest firearm mortality rates in the nation.

“That is due in part to our gun laws,” Murphy said. “In this state, it is harder to get your hands on an illegal weapon; it’s harder to get your hands on an assault weapon.”

But he said the state needs to improve its red flag laws, which allow police to seize guns from people deemed a threat to themselves or others. Connecticut recently streamlined its red flag laws, but the changes have only been in effect since June.

“There are probably a lot of people who are showing signs of danger to themselves or others that should have their weapons temporarily taken away,” Murphy said. “Connecticut can do better when it comes to the administration of its red flag laws.”

A relatively small part of the population owns many of the guns in the U.S.

About half of the nation’s guns are owned by 3% of America’s population, according to a 2016 study by Harvard and Northeastern universities. That’s about 7.7 million people possessing an average of 17 guns each, according to the study.

But as NPR reports, researchers found that only one-quarter of Americans own guns, despite the country having more guns than people, according to a study of global firearm ownership.

“What’s happening is that a very small number of Americans are buying lots and lots of weapons,” Murphy said. “Not all of those people are dangerous, but some of them are. And that’s what we really have to watch and track.”

Murphy says gun reform takes years. And he hopes to see more changes over time.

From the outside, Murphy said it looked like politicians were doing nothing as there was a string of mass shootings – shooting after shooting after shooting. “What was actually happening is that we were getting closer to passing something substantial,” Murphy said. “After each mass shooting, whether it was Las Vegas, or Orlando, or Parkland or El Paso, we had a more serious conversation with more Republican partners.”

Murphy said it took years to get to the point where Republicans and Democrats could agree on a gun safety reform package like the Bipartisan Safer Communities Act.

“It was the moment at which we had achieved such cumulative strength over time that we were finally able to pass something,” Murphy said. “We had more activists, we had more money on the outside. But we also finally had just enough Republican partners on the inside, after building up those partnerships over 10 years, to get something serious done.”

He touted $15 billion in the law to fund mental health, school and community safety, which he said will allow more counselors to help children and interrupt cycles of violence in cities.

“I’m somebody that doesn’t believe our gun violence problem is primarily a mental health problem,” Murphy said. “But there’s no doubt that if you get more services to kids in crisis, it will lead to some lower levels of violence.”

Murphy’s bill didn’t include other things Democrats wanted like a federal assault weapons ban or universal background checks on gun purchases. Murphy said he would still like to see those things, but “that’s just not how politics work.”

“You don’t get everything all at once,” Murphy said. “You make progress. And you have faith that when people see the results of that progress, they’ll want more.”