Where do you aim if you want to "shoot to incapacitate"?
No such place exists on the body. Even using small, low-powered rounds like a .22 rimfire short carry extreme risk of death no matter where you aim.
The answer is more simple. Don't pull out that gun unless what the person is doing warrants death. I don't know that attempting to apprehend a DUI is worth killing someone over. If you're responding to a domestic violence situation where someone's running around with a knife though, it's likely that a gun isn't a terrible consideration.
I think the real issue is getting in the competitive zone. "I'm not going to let this pero beat me" instead of considering if the cure is worse than the disease.