Hasan had spent six years dealing with the mental wreckage of war at the Walter Reed Army Medical Center in Washington and, since July, at Fort Hood’s Darnall Army Medical Center. His own susceptibility to mental problems was likely heightened because he was pretty much a loner: he wasn’t married or in a relationship. After his parents died a decade ago, he seemed to become more religious. Absent close family, he spent much of his time counseling soldiers whose minds and bodies were scarred in combat.