Multiple shooters must be considered, and would help explain the varying lethality of the shots, just as you say. The alibi comment that was made is an interesting angle as well. I can't believe that this is one, lone nut. I can't help but think he would have made some mistake by now, but who knows.
BTW, WTOP news at the top of the hour says victim "in hospital" so I'm assuming that means still alive. Let's hope so.
No, the victim died about half an hour ago.