Unlicensed shotgun possession in NYC is a felony. I presume, since he was a "Pennsylvania man" and since NYC/NYS do not issue nonresident licenses that he didn't have one.
What's interesting about this story is how they caught him - since the Holland Tunnel has approximately 100 000 vehicles/day, they must have some high-tech screening.
But he never made it into New York. He was caught in the Port Authority on the New Jersey side.
I see these big giant “scanners” that are installed on all the crossings going into New York. So I have a feeling they can “see through” things as see guns, weapons, explosives, or whatever. But I don’t know, I am just guessing