I strongly disagree. Anytime an officer-involved shooting occurs, the incident is closely scrutinized for compliance with deadly-force protocols.
By watching the dash-cam video, a 3rd-grader could tell this was a bad shooting.
The cop would have been charged with assault regardless of whether or not the victim survived the shooting.
I'm sorry, but most "thorough investigations" are performed by people who are pro-police and work with the police. Unless the evidence is overwhelming, the police are excused. Even at trial, they always get sympathetic juries.