We originally posted the Sticky on this subject to make our members aware of a risk that they may not have known about and that they can mitigate. Denial is not a useful response, and questions about investigative techniques are not really within our scope here (nor does the technology stand still).
I would like to broaden the discussion to better illustrate where and how the subject matter of the Sticky fits into the whole ST&T spectrum.
Let's start by assuming that everyone knows and abides by the relevant use of force laws in the jurisdiction and that everyone is of a mindset to resort to the use of deadly force only as a last resort when it is absolutely necessary.
Given those assumptions (and the assumption that a person has not left his firearm at home), it seems to me that a person faces three risks if he becomes involved in a confrontation that requires the use of deadly force outside of his home.
The first is the risk that he or she may not prevail. Just as almost every male regards himself as an excellent driver, most armed citizens seem to think that they have the skills to handle any "punk" that they may encounter on the street. Unfortunately, that may not be true.
There are ways of mitigating that risk. They include
skill and training, including mastering the art of situational awareness; and
avoidance, including staying away from certain places, choosing parking places wisely, withdrawing to safety if there are indications of trouble, and so on. The latter can reduce the likelihood of having to use deadly force, and the former can increase our success rate should force become necessary.
The second risk is that of injuring an innocent bystander. Skill and training, situational awareness, and avoidance are applicable for mitigating that risk also.
The third risk involves the possibility that, even if one has used deadly force only when it was absolutely necessary and in a completely lawful manner, things may not go well for the actor after the incident. Problems can manifest themselves either in the area of a criminal investigations or in that of possible civil suits. This goes back to the realization that the old saw "a good shoot is a good shoot" is just not very helpful. This has been discussed
here.
The fact is, even if the actor has done only that which was necessary and unavoidable, it is quite likely that only he or she will know that. Others will have to piece together a picture of what had been a live action event using what evidence can be gathered after the fact, and that evidence is likely to be incomplete, fragmentary, sometimes unclear, and possibly contradictory.
It is at that point that something that the actor had said before the incident or that he or she has said afterwards, if it can can be interpreted unfavorably, has the potential to be damaging.
That risk can be avoided completely by being careful about what one creates. No one should attempt to rely on any other mitigation technique.