The wife. Who is a certified anti-gunner trying to fuck over her gun-nut husband.*
While I find it a bit creepy that the USPS “permanently” stores images of every piece of mail it handles, still, it warms my heart to see the FBI actually getting something right.
Not that Major Bloombutt or Teh Won will ever admit they were wrong about who sent the letters.
___________________
* Who, btw, has now filed for divorce from the nutbag shrew. Moral to story: Never marry an unsuccessful actress.