Of course not.  No two situations are alike.  Some, maybe most, cop shootings are justified, but a lot of them don't appear to be.  The Jessica Hernandez shooting comes to mind.  The investigation showed that Jessica could not have been driving more than 11 mph, at most, and the cop she was driving at was able to but his left hand on the front left hood of the car, stepped around the car, and shot her with his right hand several times through the window.  The cop's life wasn't really in danger.  He was just pissed off at her non-compliance.

Had she been arrested and gone to trial, she'd have been sent to jail for a year, at most.  She would not have been given the death penalty.  But the cops gave it to her.