If he developed PTSD while serving our country then it does matter.  But the real question is whether an obvious psychotic/schizophrenic should receive the death penalty - one of the elements of a 1st degree murder conviction is 'intent'.  But how can you say he intended to commit those acts if he had voices in his head telling him what to do?  And what would executing him serve?  Put others on notice that they'll be punished if they become mentally ill?  Keep in mind that he did reach out for help, and didn't get it.

Nah...no way the death penalty sticks.  Lock him away in the loony bin for the rest of his life.