'And, given the fact that the deceased was a gang member and had earlier fired on an officer, it is well within reason that he is now 'deceased'.'
This is a different dude. That said, you are surrounded by the cops, have a police dog at your feet, are told to drop your weapon, but you say "I got my finger on the trigger". Cops fault for sure. Shoot the dumb bastard.
If he dropped the shotty, yes.
If not, hmm.
What was he doing in the neighbor's yard with a loaded shotty anyway?