I've thought about this before and have decided that, no, I will not render aide.
First, I was just forced to shoot the man (or woman) because he or she was trying to kill me. That right there makes me hesitant to care about his or her well being.
Second, there is always the chance that he or she is either playing possum or dazed and the moment I start "rendering aide" they come out of it. Others have already mentioned the idea of a second weapon that was hidden. They could also be hopped up on drugs that make them more aggressive and/or stronger than usual.
Third, you said that you would restrain them and wear rubber gloves. So, not only do I have to carry a gun, a knife, spare mags and a back up gun or knife. Now, I have to carry rubber gloves, zip ties, hand cuffs (or some other restraint), basic medical first aide kit,.......... where does it end?
Fourth, I am not a paramedic.
Fifth, after a shooting I'm almost sure experience an adrenaline dump and other physical effects. I will be shaking, scared, and generally not in any condition to be assessing the physical well being of anyone.
Sixth, this falls under "not my job" category.
Also, you mentioned wearing rubber gloves. But what if you need to give mouth-to-mouth and there is blood in the way, are you also going to start carrying a mouth guard?
What if you are injured yourself and in too much shock to know it? Adrenaline can keep you from feeling gun shot wounds, even breaks and stabs. You need to get away to safety and start evaluating yourself before you take time to worry about someone else, particularly the person who put you in that situation to begin with.
Lastly, until the police arrive and he is loaded into an ambulance you have no assurance that the situation is truly over. His buddies could be around the corner and on their way. A civilian passery-by may misunderstand the situation and get involved. There are just WAAAAYYYY too many variables.
The best and most important thing is to get away to safety.
Get away to safety.
Let me say that again: GET AWAY TO SAFETY.
Call the police and keep your mouth shut until your lawyer arrives.