BOSTON — Most lawmakers seem to agree that something needs to be done about so-called “ghost guns,” but a fierce debate continues about the extent of additional gun regulation such as restricting where legal gun owners can carry and updating the statewide ban on assault weapons.

Massachusetts has the lowest rate of firearms fatalities in the contiguous United States, but reform supporters argued during a Committee on Public Safety hearing Tuesday that the problem of gun violence is still potent enough to warrant additional action, particularly amid the increasing presence of untraceable “ghost guns.”

These weapons are often made or assembled at home and lack serial numbers with which they can be traced. They can be assembled from pre-packaged kits or 3D-printed.

Law enforcement officials including Attorney General Andrea Campbell have been sounding the alarm about the increase in the number of ghost guns on Massachusetts streets.

“A majority of the crime guns that are currently recovered in Boston and in Springfield and in some other urban communities are in fact ghost guns. Ghost guns are just as deadly as a gun that is bought from a licensed gun dealer. ... And currently, under Massachusetts law, these are not prohibited guns and it’s creating a significant public safety problem,” said Rep. David Linsky, who filed a bill to regulate the untraceable weapons as well as 13 other bills before the committee on Tuesday.

He added that if the Committee on Public Safety favorably recommends any of the 53 bills heard at Tuesday’s hearing, he hoped it would be one that deals with ghost guns.

“These unregulated parts and kits make it possible for a whole range of prohibited and dangerous individuals — people with criminal convictions, people with severe mental health issues, people in crisis — to access firearms by buying parts online with no background check,” said Samuel Levy, counsel for Everytown for Gun Safety.

House and Senate Democrats spent months this year at odds over whether to involve the Committee on Public Safety in the review of a bill authored by Judiciary Committee Co-Chair Rep. Michael Day of Stoneham. The House ultimately circumvented the joint committee process and approved Day’s controversial legislation 120-38 in October. The Senate plans to take up its own version of gun reform in 2024.

Rep. Christopher Markey, a Democrat, said in October that he had concerns about Day’s bill and criticized its ban on carrying firearms in some spaces, but doubled down on the ghost gun issue.

“I have my own ideas of why it’s difficult, but no one has come up on the pro-Second Amendment side to say ghost guns are a problem, and for anyone to say that they’re not, they’re naive,” Markey said at the time.

On Tuesday, members of the Gun Owners Action League, who opposed Day’s bill, testified in opposition to most of the bills before the committee that would have restricted legal gun ownership.

GOAL’s Director of Public Policy Mike Harris was critical of over-regulating ghost guns during his testimony, though he said there is room to increase penalties for illegal sales.

“The right to build one’s own gun in their own home for their own personal use has been a protected right in the United States since the 1600s. The term ghost gun is just another political term with a flexible definition used to scare people,” he said.

Harris said it is illegal to sell a gun to an unlicensed person, and illegal to use a gun in a crime, so new laws “would be kind of redundant and ineffective at reducing crime.”

“It could be beneficial, however, if we decided to increase penalties on those found to be illegally selling and transferring guns, or to get an actual definition of what a ghost gun is,” he said. “We’ve heard anything from a 3D-printed gun, all the way to a firearm with a scratched off serial number. So getting a real definition of what a ghost gun is put into law, if we want to do that, would be beneficial.”

GOAL members spoke out against bills — that are similar to provisions included within the House’s gun reform bill — that would limit the presence of firearms in certain public spaces and update the state’s ban on assault weapons.

A Linsky bill to prohibit carrying firearms in “sensitive places” (H 2359) would ban guns in government buildings, polling places, behavioral health clinics, places of worship, libraries, public playgrounds, public parks, any program licensed to provide services for children or young adults, nursery schools, summer camps, locations for disability services, homeless shelters, domestic violence shelters, colleges and universities, public and private schools, public transit, train and bus stations, airports, bars, theaters, stadiums, racetracks, museums, shopping malls and more.

Ilyse Levine-Kanji and Ellen Leigh, who are both members of the pro-gun control group Moms Demand Action, spoke about how this bill, if passed, would make them both feel more comfortable in public places.

Levine-Kanji and Leigh both told personal stories about being impacted by gun violence. Levine-Kanji’s co-workers were killed during a mass shooting in her office, and Leigh described having her life threatened with a gun.

Rep. Steven Xiarhos, a Republican who voted against Day’s bill in the House last month, asked both women how the bill prohibiting guns in certain places keeps people safe.

“How do we make sure that a criminal, or someone that’s mentally ill with a knife or a gun, doesn’t go into those areas, don’t follow the law and commit horrible crimes, like 30 years ago what happened to you?” Xiarhos asked Leigh. “How do we prevent those people from coming to those areas and doing something horrible when there’s nobody there to stop it?”

Levine-Kanji replied that guns can be used to intimidate people, and that accidents can happen with firearms.

“It’s also my right to go to a polling place and not see people with guns standing outside. Why do you need to have a gun that would be intimidating for me?” she said. “Also, more guns don’t make us safer. More guns make us have more tragedies.”

Sen. John Velis of Westfield said he was concerned with a lot of the legislation before the committee, with the exception of the ghost gun bill.

He described a conversation he recently had with a retired judge, where he asked how many gun-related crimes the judge presided over in his 20-year career that involved use of a legal firearm by a licensed owner.

“And his answer absolutely blew me away. The answer was one, in 20-plus years, multiple years, of hearing these cases,” Velis said.

He added, “I think it’s really important as we consider all of this legislation, to kind of tackle all of the challenges that we see in the commonwealth, and really try to be bold in some of our solutions, because there is an element out there in terms of gun violence ... and my concern is that a lot of this legislation, probably with the very notable exception of the ghost gun stuff ... I’m not necessarily sure how it impacts that.”

Gun shop owner Jesse Thorpe said he would not comply with the “sensitive places” firearm ban.

“These criminals out there have firearms, and you’re going to tell me I can’t carry a gun to the movie theater? Or I can’t carry a gun to the polling place where I go to vote, where a criminal could have a gun and shoot me or my wife while we’re voting? It’s not going to happen,” he said.

Thorpe also pushed back on a Linsky bill that would enhance the state’s semi-automatic firearms law (H 2361).

Linsky said his bill would clarify what guns are included under the state’s assault weapons ban, which was originally modeled after federal legislation.

Deputy director of the Attorney General’s Gun Violence Prevention Unit Ryan Mingo encouraged updating state laws regarding assault weapons.

One thing the bill would do, Mingo said, is make it clear that any temporary modifications made to a weapon to pass a test determining if it is an assault weapon are prohibited.

Thorpe said the bill would effectively ban 80% to 90% of the guns he sells at his shop.

“They’re just common use weapons,” Thorpe said. “22 rifles, 30-06 rifles. I live in the western part of the state. We have a lot of target ranges, we have a lot of fun out here shooting, we hunt. People don’t understand out east there how people hunt for food out here to eat. Not everybody is very wealthy like the people in Newton or Watertown.”