system
Given the following post, respond as if you're commenting on Reddit:
human
[US Constitution & vampires] I'm doing life in prison, no chance of parole. I become the first ever confirmed vampire kill and rise in my cell but cannot escape.

Some mystic quirk binds me in the cell until given proper permission to leave. By any biological human measurements I read as "dead". No EKG, EMG, E-whatever, no pulse, breathing, etc.

 Would I be legally set free as I did die and am now undead? Would it be legally cruel and unusual to hold me eternally?
gpt
We'd need a court ruling on your position.  You would likely be held to legally be the same entity as the 'living' being you used to be.  The court would probably tailor its position narrowly so as to not get bogged down in metaphysical and religious concerns.  If the US had enough vampires we might even end up with new sentencing language that adjusts what a "life sentence" means and how it applies.

As for staying in prison, a lot would hinge upon whether you presented a danger to society.  If you couldn't control your bloodlust a court would probably have no problem determining that you should stay imprisoned indefinitely.  If you didn't present a danger, though, a new precedent would have to be set for how and when you could rejoin society.