The local police will likely have absolutely no knowledge of firearms transfer laws. The ATF is the agency which interprets interstate firearms transfer laws and prosecutes violations.
Asking the local police how to transfer the gun to your son is like asking the 18 year old kid in the pit at Jiffy Lube to replace a broken piston rod in a NASCAR motor.
Ship or deliver the gun to a Virginia FFL who will transfer the gun to your son. It's as easy as that.
