New and conflicting laws around the purchase of firearms are taking effect across different states this week.

In California, the law now requires credit card companies to provide banks with special retail codes for gun stores in order to help track

their sales. But just the opposite is happening in Georgia, Iowa, Tennessee and

Wyoming where it's now illegal for banks and credit card companies to track that information.

Stephanie Sigh has more on that story and joins us now.

Stephanie?

Um, no, credit cards have been used to buy guns in some of the nation's deadliest

mass shootings in 2012 the gunman in the Aurora Colorado movie theater

shooting charged 11,000 dollars to buy guns, ammunition, and tactical gear.

In 2016, the Pulse nightclub shooter in Orlando put more than $20,000 on credit cards.

And in 2017, after the Las Vegas Massacre

killed 59 people, police found four credit cards

that the shooter used to pay for part of his $95,000 rampage.

This new front in tackling mass shootings has divided conservative and liberal states.

For more, I'm joined by David Leib, who's been covering this for the Associated Press.

David, thank you so much for joining the news hour.

Can you just briefly remind us how merchant codes work?

Are those what you see in your end of your credit card statements that give you an idea,

for example, of how much you spend on groceries or clothes?

Yes, exactly. That is probably the most common way that a consumer would be familiar with these, a merchant category code is set

by the International Organization of Standardization. That's a big mouthful, but that's a group that sets standards for a variety of fields across the world, actually.

So they have come up with a new four-digit code that can be assigned to stores that primarily sell guns and ammunition.

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