Are zombies legally responsible for their actions and could they be prosecuted for murder if they ate your mom? These are the questions being examined by legal expert Ryan Davidson. He specializes in hypothetical cases involving fictional characters, which I didn't know was a law specialty. It's for his blog Law and The Multiverse. He'll be discussing the implications and problems with prosecuting the undead today at Wondercon in California. He says, "If zombies are effectively unconscious, then they would be incapable of performing voluntary actions and thus immune to criminal liability (or civil liability, for that matter),". A good point. Once they are mindless eating machines they can't help themselves anymore than a lion can stop himself from eating a zebra. Humans are simply his food. Davidson argues that if the zombies can think rationally, then maybe they are committing murder, (Like in I am Legend, for example).
I would argue that even in the case where the zombie does realize what he's doing he still shouldn't be prosecuted. The central task of any organism, alive or undead, is to feed itself and reproduce. If human brains are their only source of sustenance and the only way they can reproduce is by biting people and turning them into zombies they are just following the biological imperative. It doesn't really matter because if the zombocalypse does come society is going to break down. That includes the judicial system. How are you going to sue anyone if the judges and lawyers are either zombies or zombie lunch?
Now watch a zombie fight a shark below in a scene from Lucio Fulci's classic Zombie.