You post comes halfway to admitting that it may have happened before new rules came into place and very well may still be happening in other jurisdictions. We have had some pretty recent incidents of police not following the rules.
Now here is a question for you. Let us assume that a police officer does discharge his firearm and it seems to have been something more like a warning shot, what are the odds of him or her actually being charged? I suspect that he or she might be disciplined but not even fired.
Often, it can be a case where the cop kills somebody in a bad shooting and gets charged with a low level manslaughter charge. Good odds Virginia would try to put a needle in a normal person's arm.
What I am arguing for is some kind of sane charge.
Everything depends on context, and like everything else in LE (and politics too for that matter) there are certain variables that can't be accounted for, but any use of a firearm on duty that isn't justifiable that does not result in injury or death could be anything from a letter to file, to time off w/o pay to dismissal, depending on agency standards.
I'll tell you where the real punishment comes in.
If you're one of the guys and you screw up with
anything related to self gun handling or use the shame of it (it doesn't need to involve injury or death either) will follow you around like a tail for the rest of your LE career.
Case in point. When a local CLEO retired I was asked to speak at his retirement dinner, and before I could even say yes or no I knew why.
When this officer was a young guy. 30 + years back he was part of his departmental shooting team, and at some point there was a team photo taken where the officers were turned out in dress uniforms with their revolvers held muzzle up in the strong hand.
He was the only guy that had his finger inside the trigger guard, on the trigger...
I built a whole comedy routine around a blown up version of that photo, and as is my prerogative as a long time certified firearms instructor I critiqued his technique, training, skill and family background. What he whispered in my ear when he was finished would be auto-censored heavily, but we're on friendly terms.
A less funny example is a particular officer that was known to me that negligently discharged a firearm he was showing to a fellow officer off duty where the round passed through the calf of the officer w/o doing major structural damage but ending up around 200K in medical bills, which the negligent shooter was responsible for but wasn't disciplined past some TOWO, but not to many fellow officers wanted anything to do with him and he found other employment.
Officers that accidentally injure innocent members of the public in a similar fashion would face much harsher action in agency and in civil court as well, although the municipality would most likely foot the bill if the incident occurred on-duty.
Second bolded - The problem in charging any LEO with duty related 1st degree murder is the requirement for a "premeditated" killing - if the encounter is happenstance, and pretty much every encounter an officer is involved with is happenstance.