WAIT I DIDNTT GET IT, WHO DIED_? THE GUY WHO WAS HAVING ORAL SEX WITH THE PRIEST?

Peter (dark hair priest) has been doing sexual favors and selling the church orphans to keep the church afloat. Oral sex guy is the newspaper heir who is one of the supporters. Peter also started giving John (serial killer) drugs since he was a child, thus able to presumably manipulate him to where John is now. The newspaper mentions sister Mary’s death. She’s the nun with round glasses in the 1926 flashbacks (when John is still a child (the one with bandages on his face)) my guess is peters been shady for a long time and sister Mary killed her self in shock, or Peter had John kill her for one reason or another