By giving Death penalty for Abu Salem, indirectly he is been relived. Instead he has to be sentenced for life regurous impressionment till to death and not to allow any body to visit him during the tenure. Say like in Solitory Cell.
He has to experience the pain and feel for his deeds.
If he has given Death penalty, he may lost his life, but how can he experience the pain that can never be put out of lacks of Indians.
