No this was an idea that his brain could not shut off, fueled by loss of Mother & Grand Father,dealing with the ravages of depression, & muddled by the meds [which can have very weird sideeffects of the person using them] A thought can enter the mind & not be shut off unless the person is either dead or the thought has been completed. I should know, I am dealing with the effects of multiple head injuries & take a large doses of meds to deal with them. But you also have to add talk therapy to help deal with issues & NOT just rely on the meds to do everything. Then he should have not been able to purchase the pistol, in his medical condition/s, he was not in his right Army from the Reserves [they do not promote as fast as the regular forces do] so calling him a looser because of his age versus his rank is wrong folks.
Deaths usually slow you down...not aggravate you. And the deaths were months ago.
I hope you find relief and better health. I may be wrong, often am, but I did not see where the shooter had experienced brain trauma, i thought he saw no combat during his tour?