Eating meat slaughtered by a person who has moved from one kaafir religion to another kaafir religion
Question

                If a Christian becomes an atheist communist or a Buddhist, is it permissible to eat meat slaughtered by him? Or if a Jew becomes a Christian, is it permissible to eat meat slaughtered by him?
Praise be to Allah.The fuqahaa’ are agreed that if a person from the People of the Book 
          moves to a religion which is not that of the People of the Book, meat 
          that is slaughtered by him cannot be eaten. But if he moves from his 
          religion to another religion of the People of the Book, such as a Jew 
          who becomes a Christian or vice versa, then most of the Hanafi, Maaliki, 
          Shaafa'i (according to one view) and Hanbali fuqaha’ say that it is 
          permissible to eat meat slaughtered by him. And Allaah knows best.