Crime and Punishment

The Maryland General Assembly's legislative session is at its height now, accompanied by reintroduction of various hardy perennial proposals, including the abolition of the death penalty, which seems to be gaining momentum this year. The disturbing revelations (through DNA tests) of mistakenly convicted people on death row and the fact that the execution process (with appeals) costs more than supporting a prisoner for life make the death penalty appear especially problematic. So I started thinking about possible future enhancements of or alternatives to execution as punishment for heinous crimes, some of which I've encountered in SF stories:

Simplest solution to the high cost of the death sentencing process: Put the malefactor in a permanent coma and harvest his organs for transplant, killing him only after all usable spare parts have been extracted.

Place his body in suspended animation and use his brain to pilot an otherwise unmanned cargo spaceship. This was the premise of a story I read a long time ago, but I don't remember what stopped the disembodied pilot from simply absconding with the ship.

Sentence him to lifelong solitary confinement in a sealed, completely automated and computerized cell, with no human contact. No more problems with prison violence!

Link him to a virtual reality program that forces him to experience his victim's suffering in precise detail, over and over for the rest of his life.

Same system, but instead force him to virtually commit the crime over and over in an endless loop.

Wire his brain to turn him into a mindless zombie and use him for hazardous physical labor.

Alter his brain through either surgery or drugs to make him completely docile, incapable of violence or rebellion.

Release him into society as an unperson, declared "invisible," so that no one will interact with him in any way, and he has to survive by scrounging for his basic needs. This idea also comes from a story I read, and, again, I don't remember how the author dealt with the danger that the convict, having nothing else to lose, might go on a rampage of destruction. That problem could be avoided by first reprogramming him, as above.

Wipe his personality completely. Reprogram him with a totally compliant, nonviolent personality. Would this procedure, if feasible, constitute the most humane solution or the ultimate violation of human rights?