Many folks consider fireworks a non-negotiable part of their 4th of July celebrations. But not every state agrees. So there are always enthusiasts crossing state lines to buy up fireworks and bring them home. Could you actually get caught for transporting fireworks? And if so, what would happen?

First, how would you get caught? Police would need to be searching your vehicle. If they stop you for a traffic infraction, they don’t need a warrant to do this. They do need some evidence suggesting you’ve committed a crime. For example, a visible shopping bag from a fireworks store across the border. But this isn’t the only way they’ll stop you.

Multiple drivers have reported checkpoints at state border crossings to search for fireworks. For example, Henry and Mary Haurand live in Salt Lake City but were driving into California when Cal Fire stopped them. Henry said, “We come in and out of California, and this is the first time they’ve ever asked us to open the trailer.” What were the authorities searching for? Illegal fireworks.

To be fair, California is a unique case because it already has Food and Agriculture Inspection Points to search cars for non-native plants at all its border crossings. It seems that during the summertime, Cal Fire may set up at the same checkpoints. But transporting fireworks across any state line could be a federal offense.

The federal law 18 U.S.C. § 836 prohibits transporting fireworks into a state where it is illegal to sell or use them. So if you are caught driving fireworks across state lines you will have to deal with local laws. But you have also broken a federal law, so you might get charged twice over.

The chances of you facing a traffic stop searching for fireworks–like the Haurands–may not be huge. But if the police do decide to crack down this summer, you could get in big trouble.