What indication do you have that this is “exactly as it seems”?
Simple logic
1. A prisoner in a locked single cell is found dead with a sheet wrapped around his neck and tied to the bed frame.
2. The prisoner had previously been considered suicidal
3. The prisoner, a multimillionaire, lives in a 50,000 square foot house on his own island and now is incarcerated in a 8x 10 foot cell with no prospect of leaving same for 45 years.
4. The prisoner has good reason to believe he will never enjoy any of the luxury in life he is used to.
5. The prisoner has no reason to continue living.