An armed man, holding a loaded weapon is called "Deadly Physical Force" for a reason
and the police responded 'in kind' !
Shoot to injure only occurs in movies like "Blazing Saddles".
The FBI did a sting operation by driving undercover agents up and down North Broad Street in hood popular cars. When one would get stopped, there was a criminal record to match the driver. All the sudden a weapon would be recovered from the vehicle when none was there prior to the stop.
Not all cops are pure as a prom date. Their logic was that they were just getting people off the street who would be committing a crime soon anyway based on their record.