I’m curious how the law was broken. Did a licensed dealer not do a background check or was this through a private seller. If the licensed dealer didn’t do a background check then the licensed violated the law. If it was a private sell a background check may not be required.
They bought a handgun and several long guns from a non-licensee, and then took them back to CO, also crimes under Fed law.
And there’s your trouble. The laws are so convoluted that you can’t be sure you’re not violating something. And you can be good to go in your home state but commit felonies by simply crossing a state line. Free men shouldn’t have to be burdened in that way.