Passenger 389, my bad I did miss one. However as I explain in my post it wouldn't increase safety levels as so many loaded weapons are freely available and can be deployed easily to land side at any US airport.
Better to use resources to ensure weapons are not in the wrong hands. The FBI is being lambasted for returning the gun to the perpetrator, but I'm guessing that Alaskan law gave them little choice. The law should have let them keep the gun and make sure he couldn't get another one.