Zombie Attacks / Insanity Plea?

Recently, a bizarre rash of crimes have occurred dealing with individuals eating parts of other individual’s bodies. These “zombie” attacks are odd to say the least, however, legally, one must ask, are these individuals legally insane? Could they use this as a defense? Not Guilty by reason of Insanity? Here is a recent news article that explores one of those specific cases (NOTE: Infamous serial killer Jeffrey Dahmer who ate parts of his victims was found criminally responsible, the court rejected his insanity defense). ; Please see reading material at: http://e.standard.net/stories/2012/06/19/accused-brain-eating-cannibal-moved-mental-hospital

Explain in a 1 page discussion why you do or do not think these individuals will have a successful insanity defense and make sure to apply the necessary elements of insanity to your answer.