Flashbacks come whenever we are presented with a reminder of a situation where we experienced a lack or control or a personal threat that compromised our ability to control any outcome.

This is when we have to remind ourselves that even though we have survived our past, may have seen things that were disturbing, we can develope coping skills.
Your right about the possibility of a war vet getting confused and now we see here, can be a danger to others and themselves. Perhaps you can try to look at this as a lesson for how we truely need to take these troubled vets seriously and try our best to prevent the ones that truely struggle from slipping through the cracks like this one did.

Your time in law enforcement exposed you to much of the bad, that really is the job unfortunately. Most of that job is facing people that are unhappy or deranged in some way, so it is understandable how that can be very wearing. This is when you have to dig deep and concentrate on the differnce that you made, we all have to learn that each of us can only do so much and there are going to be bad things that take place, should not take place but somehow just do take place.

You have to truely make sure that you concentrate on the things that you accomplished and that it is ok, human, to grieve things that happen like this. And believe that because such a bad thing has taken place, some other man or woman may be saved from this occurance. Many of our lessons in all our lives are from experiencing, seeing, hearing or being exposed to some very troubling events. This is when we all must truely remember, when one door closes another does open somewhere. Recognizing and making efforts to prevent in the future is a door that opens, can serve to change this outcome. We don't necessarily get to see progress all the time, ones that end up being saved from what changes come after this kind of lesson.
So, what we do have to keep in mind is that it will open a door we don't always see, however a door does open.