Are you saying the shooter's mother wasn't at the very least a supporter of the NRA?
She owned at least 4 guns and taught the school shooter how to fire weapons.
I googled the shooter's mother Nancy Lanza and the NRA and everyone seems to think she was a member of the NRA but there doesn't seem to be any hard evidence one way or the other.
P.S. What do you think of a gun owner who keeps at least 4 guns in her house while living with a crazed son?
Killed with her own guns she kept for "protection".