A current internationally famous Mufassir-E-Quran had been proved as a murderer and a 'Rajakar'[*1] recently. The murder was committed about 40 years ago during liberation war of Bangladesh.(Though the evidences are quite questionable, could easily be considered as a Political Conspiracy. However, that is not my question.)
Many people had become Muslim through his lecture. Many Muslims corrected themselves from miss-concepts. That person was sentenced to death by the war-crimes-tribunal formed recently.
My question is:
What would be the punishment for such a person in Islamic laws?
Does human have the right to punish a person who probably already been forgiven by Allah? (about being forgiven, it's only an assumption as he is a very pious man.)
[*1] : Both Bangladesh(the-then East Pakistan) and Pakistan(the-then West Pakistan) are Muslim countries. Many Bangladeshi Muslims didn't support the separation and thought their Islamic duty as to oppose the separation. Those people are called "Rajakar" and are hated by the people of Bangladesh.