[sickoflibs]

RE:”A review of the Federal statute does not indicate that it was violated either. I'd love to see this dad charged but I don't know of any crime to charge him with.”

The NRA gives this advise for such situations

First things first, if you have reasonable cause to believe the person you’re gifting a firearm to is prohibited from possessing a firearm or ammunition, or that the person will use the firearm in a crime, you are committing a felony. Don’t do this.
NRA page :Buying and Selling a Firearm: Giving Someone A Gun : Author : Outdoor Hub

[sickoflibs]

I found this one too:

II. KNOWINGLY SELL, GIVE OR OTHERWISE DISPOSE OF ANY FIREARM OR AMMUNITION TO ANY PERSON WHO FALLS WITHIN ONE OF THE ABOVE CATEGORIES:
18 USC § 922(d). Punishable by up to 10 years imprisonment.
Justice.gov :QUICK REFERENCE TO FEDERAL FIREARMS LAWS