Suppose you believe that final death is an appropriate punishment for someone's crime. You also believe cryonics has probability p of working, where p is too small for you to sign up for cryonics. Should you allow the prisoner to be frozen?
If cryonics doesn't work, it doesn't make a difference; and if cryonics does, you shouldn't. Thus there is no reason to allow the prisoner to sign up for cryonics.
Notice that this conclusion doesn't depend on the probability of cryonics working, or on how certain you are the prisoner is guilty, for any certainty sufficient to justify him being executed.
If someone is sentenced to life in prison or the death penalty, should they also be prohibited from signing up for cryonics? Specifically, I'm referring to people like these: http://en.wikipedia.org/wiki/List_of_United_States_death_row_inmates
I am not talking about providing it for them, just allowing them to sign up for it provided they can somehow get enough money together and allowing a response team into the prison to retrieve the body after the prisoner has died or been executed by lethal injection. I think they should be allowed access to cryonics, because we don't know enough yet about the brain to determine how much of their criminal behavior is due to mental illness/disorder and how much is due to free will. It may be possible to diagnose and cure people like Jeffrey Dahmer in the future before they commit any crimes, or to cure those already in prison such that they won't commit any more crimes.
As cryonics gets more and more popular, this will become an issue, especially when the first death row inmate wants to sign up for it.