While Attorney General Andrea Campbell works to set up a new gun law enforcement unit in her office, she’s also calling on credit card companies to play a role in combating gun violence.

Last week, Campbell joined 13 attorneys general from other states in sending a letter to the four major credit card companies, urging them to help “disrupt” gun violence. Visa, American Express, MasterCard and Discover earlier this month announced a pause on plans to adopt a new code distinctly categorizing sales at gun stores, a feature supporters say would help flag suspicious purchases made with credit cards. The AGs’ letter argues that merchant category codes are routine and that political pushback from other states should not impede the move.

“If you can track us going to Walmart and buying milk, why not guns? Which gives law enforcement critical tools to not only look at where people are buying, if gun hoarding is happening, but also if someone illegally purchased a weapon and used it in some horrific crime, law enforcement can go after them and hold them accountable,” Campbell said on Boston Public Radio Friday.

The attorney general announced plans to create a gun safety unit at her inauguration in January. She said Friday that she’s starting an internal working group and reaching out to law enforcement as she develops both the gun unit and a police accountability unit.

She described the gun enforcement unit as a one-stop shop within her office for sharing best practices around issues like firearm trafficking and the manufacturing of so-called ghost guns, untraceable weapons assembled from parts that are often bought online or made with 3-D printers.

“We have folks in our state police unit that are doing trainings every day with local law enforcement,” Campbell said. “We need legislative solutions, as well, to keep folks from being able to manufacture these weapons in Massachusetts and sell them. In addition, this same unit can also address gun violence in the community and make sure that survivors are getting the resources they need.”

Campbell is not alone in eyeing legislative action on guns. Gov. Maura Healey supports legislation banning ghost guns, and House Speaker Ron Mariano has said he wants to work this session on further strengthening the state’s gun laws. Next Thursday, volunteers from Moms Demand Action for Gun Sense plan to visit the State House to lobby for what they describe as comprehensive gun safety legislation.

Campbell also touched on the deluge of sports-betting ads now that the industry is up and running in Massachusetts.

Campbell said she doesn’t plan to stand in the way of the sports-betting law passed last summer, but that her office wants to protect consumers, particularly young people.

She’s been in communication with the state Gaming Commission as its members develop regulations, and said she wants there to be guardrails that prevent athletes, influencers and experts from making money by recommending particular wagers.

“They shouldn’t get paid, for example, for encouraging you to place a certain bet that will likely lose and get a percentage of those losses,” Campbell said.