BB Guns

The Graves Act:

I kind of understand this story, except for this part:

Now, the simple unlawful possession of any firearm can bring mandatory penalties for anyone who pleads guilty to or is convicted of that crime alone.

OK, but how is a BB gun "a firearm"? They sell them in the toy department around here.

Neither Narciso, nor his father knew they broke the law by having the gun without a firearms registration card, both men said.

"If we knew it was illegal, my dad never would have gotten it," Narciso said.

And it proved ineffective in controlling the problem in the attic, they said.

"That gun couldn't even kill a squirrel," the father, Emiliano Narciso, said.

Seriously, what? You need a license to own a BB gun in New Jersey?

This isn't a 2nd Amendment issue to my way of thinking, because BB guns don't rise to the level of "arms." Still, is this really a case of "reasonable restriction"?