Innocent or Guilty, the guy is dying and quickly, and represents no danger to any human being.

The fact that he is dying means, he is in no position to press ahead with any further legal challenge to a conviction, which might very well be overturned if he were well enough to do so.

The truth of the matter may never now be known. The least we can do is send a potentially innocent man, who will neither be in any position to do any other any person harm - nor equally be free to prove his innocence, home to die.