I would think at age 79 I would want to come clean and get right with the Lord. How anyone could live with this on their conscience this long is beyond me. This is not the early 50's and he cannot claim the stupidity of youth. He will meet his Maker and will confess but it will be too late.
The thing inside him remains. If this one lives to be 100 in order to rid himself of the raging hate, the resolution must come from him.