Actually, truth be told, they do keep the bodies of prisoners with longer-than-life sentences (as in the case of serial killers with multiple life-sentence-penalty charges) until their sentence is up (though they don't keep the body in the cell - just in the morgue)...so I guess suicide is still a punishable offense. Of course, attempted suicide (when you fail to kill yourself) is always punished by law.

Which is kinda unfeeling...the person is so miserable with their existence that they try to end it, and when they fail they get sent to prison for it. Ah, the system of slavery and control at it's finest....