The only drugs found were the "plants" in one of the squad cars.
I found two articles that mentioned Mr. Tuttle was shot through a window as he lay dying on the floor, 30 minutes after the gunfight. I can't find these anymore.
None of of this would have been known, except by the efforts of private investigators hired by the family.
Fits what I saw back in the 70’s. BIL was a cop. Showed me his throw-down gun, wrapped in Saran Wrap. All the cops had one in their cruiser to plant if they were forced to shoot someone. Told me he was developing the “cop attitude” and was quitting. Explained that everyone who wan’t a cop was a “perp”, including me. You were either a criminal or were going to commit a crime.