I was unaware there was a gunfight in the offing. Are you on the right thread?
You might get away with pepper spraying an unarmed attacker in Santa Monica. If you shot him, you’d go to prison for a long time.
I’m sure those who attack mail trucks are armed. Aren’t you? A federal employee who uses arms to protect himself and the mail wouldn’t be charged. There was no “you/me” in this scenario.