Honestly, valid.
I mean, are you saying a murderer can't support the death penalty for murderers? Sure, they're saying they deserve to die for their crimes. Maybe they feel that way. Maybe they made a mistake and they believe their death is owed to the families of the victims. You would think we would all be in favour of self preservation, but if you faced a lifetime of prison and prison food and dealing with prison guards telling you when and where to piss... you might take such a point of view. I couldn't imagine thinking people like me should die, but I've never seriously hurt anybody like that.
So I suppose the question is, does he think that what he did is an exception, or no?