Despite the media most of the United states is not Chicago, shootings' are not as common as some might think. Second cops are not delta force. Most police officers don't even want to shoot, and most police departments don't encourage outside training. Most of a police officer's marksmen training is on basic qualifications. Not advanced placement of fire. So a cop shooting is little different from a civilian shooting. In other words there is little other then a basic study of anatomy in high school that tells him where to aim. Additionally if the adversary in this case was attacking adrenaline comes in and the officer is under stress. That means the officer has to decide in the situation if his life is in danger, what skills and tools he has to fight back. Now the story says he was moonlighting as a rentacop that means he might not have had a tazer or some of the other gear issued by his police agency. Additionally it doesn't state if he had a partner. Those can be factors as it would limit is ability to respond and make him more likely to have to respond with lethal force.
Statistically speaking when in a officer involved shooting the number of rounds fired by a police officer is far higher then you would want to believe. When under stress and determined to employ lethal response most officers do clear the magazine. And some perpetrators' in such cases where it has happened have been shot as in the triple digits.
The tools may have changed, the training program altered to include psychological and political elements, the fire power available has increased but the truth is the training of its use has advanced little beyond Barney Fife.
Here again Terran, you're being unfair to police officers in general, we have some very well trained officers at any level of police force in this country, from the village cop, town cop, city cop, county sheriff, federal officer, military policeman, most of the officers I know are very professional, and very polite, the last thing they want to be involved in is a shooting, well next to the last thing. They will defend and protect in this order, their families, their community, their brother or sister officers, and themselves... NO Officer wants to be involved in a deadly force exchange with the "bad guys", but if they are, they are trained to fight to win, most take that responsibility very seriously,,,,
Now, handling a small handgun, whether a concealed carry piece, or duty weapon is very dependant upon discipline, discipline, discipline, and discipline,, what will you do when the BG turns and looks you in the eye with the intent of killing you? If you are a "disciplined" officer, you're training will kick in, you will draw and bring your weapon to the tactical ready, you will quickly pick up the front sight, your finger will be moving from the tactical ready position into the trigger guard, and as your sights line up you will be pressing the trigger, at least twice as your front sight covers the center of mass. Depending on the quick tactical assessment you do over the front sight, if your assailant is folding, crumbling, weapon falling away from your own center of mass, opponent is raising his hands in surrender and dropping his weapon, you will tactically disengage, your finger will rapidly come OFF the trigger and assume a rest position alongside the trigger guard, as you return to "tactical ready", should your opponent resume the fight, you will "re-engage" with the intention of "ending the fight",,,, this is the "best case scenario, if on the other hand your assailant continues his attack on you, rather than disengage, you will assess this as a "failure to stop" and begin the rapid transition of your weapon to the "ocular cranial" region, whereupon reacquiring the front sight you will press the trigger at least twice more, if your hits have been accurate, the fight is over, and your finger is OFF the Trigger and back alongside the trigger guard, if they have not depending on your training you will continue to engage the target, possibly re-acquiring the center of mass, and as others have already alluded to, you will fire until your assailant is "out of action" or your weapon is dry. Hopefully you have been moving to cover all this time and will perform a rapid tactical reload, and slingshot the slide back and allow it to slam back into battery and resume fighting for your life.
This will happen in a Nano-second, you likely will not have heard a single gunshot, due to tack-psychia effect, and you will likely fall apart as the danger subsides, and time will come back into "perpective".
I am not a tactical officer, I have never formally or informally trained or desired to be in this situation, but I have handled many angry, psychotic individuals, several who have resorted to violence, and though the only one with a serious weapon, had an 11 inch hunting knife in a back pack type bag, another individual swung a large cowboy type belt buckle, and throwing an oak desk chair missed me with both objects, and was subdued by my long time "shooting partner", who was also a co-worker, he is indeed a quick man in a fight, and was able to subdue the individual with no harm to me, the individual, or himself........he enjoyed these encounter, and I hated every minute of it, but I tried to remain calm, and de-escalate each situation, and most of the time, it ended there, but I have been hit, I have been bit, and I have been spat upon more times than I can count??? fun, fun
I was always called when a certain large individual was going off, I was scared, but I tried not to show that, remain calm, and try to "talk him down", once when law enforcement arrived he began to cry and beg me not to let them take him, I told him to be calm and sweet, and be nice to the officers and nobody got hurt... so most of the police officers I have dealt with are very fine individuals, they were just as patient, and calm, and managed each situation in a very professional manner. So please, lets not generalize when we are talking about people who spend their lives, taking care of the rest of us,,,,, yes they do make mistakes, and yes they may be afraid too????