"PHILOSOPHICALLY SPEAKING...":

Because I teach science fiction too, I always encourage my philosophy students to consider the darker applications of philosophical thought experiments -- like the brain in the vat -- as well. This proposed alternative to capital punishment is a bold, if creepy, application of philosophy's brain in the vat.
"Many people born into liberal democracies find corporal or capital punishment distasteful. We live in an age which says there are only three humane, acceptable ways to punish someone: give them a fine, force them to do “community service,” or lock them up. But why do we need to accept such a small, restrictive range of options? Perhaps, as Christopher Belshaw argues in the Journal of Controversial Ideas, it’s time to consider some radical alternatives. To punish someone is to do them harm, and sometimes, great harm indeed. As Belshaw writes, it’s to “harm them in such a way that they understand harm is being done in return for what, at least allegedly, they did.” Justice assumes some kind of connection between a crime and the punishment, or between the victim and the criminal. This makes punishment, in the main, retributive — a kind of payback for a wrong that someone has committed. ... Belshaw’s article hinges on the idea that the prison system is not fit for purpose. First, there’s the question of whether prison actually harms a criminal in the way we want. In some cases, it might succeed only in “rendering them for a period inoperative.” ... Second, and on the other hand, a bad prison sentence might cause more harm than is strictly proportional. A convict might suffer unforeseen abuse at the hands of guards or other inmates. ... Third, and especially concerning decades-long sentences, there’s a question about who prison is punishing. ... When we punish an old, memory-addled person convicted 40 years previously, are we really punishing the same person? ... Well, one option is to put criminals into a deep and reversible coma. One of the biggest problems with capital punishment is that it is irreversible. So long as there’s even a single case of a mistaken conviction, wrongfully killing someone is an egregious miscarriage of justice. But what if the criminal could always be brought back to consciousness? ... Putting someone in a coma essentially “freezes” a person’s identity. They wake up with much the same mental life as they did when they went into a coma. As such, it avoids the issues of punishing a changing person, decades later. A convict will wake up, years off their life, but can still appreciate the connection between the punishment and the crime they committed.But the biggest advantage a reversible coma has over prison, is that it’s standardized form of punishment. It’s a clear measurement of harm (i.e. a denial of x amount of years from your life) and is not open to the variables of greater and lesser harm in a prison environment. Essentially, putting prisoners in a coma establishes “years of life” as an acceptable and measurable payment for a wrong done. ... Even if you find the idea of induced comas as unspeakably horrible, Belshaw does at least leave us with a good question. Why do we assume that only one kind of punishment is the best? With science, technology, and societal values moving on all the time, might it be time to reconsider and re-examine how we ensure justice?"
bigthink.com/thinking/comas-for-convicts