Rehabilitation or Suffering

In the episode of White Bear part of the Black Mirror series we see Lenora Crichlow who is controlled and gets her memory erased everyday.  She killed a little girl, and by having her memory erased she will pay for what she did in front of a crowd who will pay to go see her. One would say if the crowd saw the consequences of her actions no one would ever do anything similar. Which sets a point, when someone sees the consequences of bad actions and the fact that he or she will not easily get away with it. The possibilities of someone repeating the same action would seem to decrease in number. If there are even any more incidents. What would be the case in a similar situation where the person who commits a crime does not remember what he or she did due to a mental illness. Would they be treated the same or should they be treated differently compared to other people who have no signs of mental illnesses.
This is a conflicting state when we realize that a lot of people who are in jail today have a mental illness but what would be the case if an individual lies or portrays characteristics of mental illness just to get a shorter sentence or a more lenient jail sentence. He or she who has past medical history of a medical illness and is convicted of committing a crime should be treated differently. We should have two different types of jails as part of the system. One for people who have history of a mental illness and are convicted of a crime today and in that jail it should consist of rehabilitative support in regards to the crime they are convicted of with a parallel resemblance to punishment for the crime they committed. Not drastic punishment but just a little different from their normal day to day lives. In specific it should help them more as a rehab due to their mental illness. In the other hand the second jail should be for those who do not have a mental illness but have convicted a crime. Those without a mental illness should serve jail time as they do today but in addition to that they should also have therapy with a psychologist. Which would help them as a rehab but focusing more in trying to retrieve their background information and realize what part of their lives or childhood has affected them on the person they are today and the reason why they committed a crime. In my point this is better than treating those with mental illness and those without a mental illness the same and just have them serve jail time and once that time is over expect them to be fully rehabilitated and not go out into the world and do the same crime one more time. It is also helping them through rehabilitation instead of suffering as it is portrayed in the episode of White Bear.