At some point early in the game, when playing as Jayden (the FBI Agent), you'll head to the house of a suspect named Nathaniel. You'll learn he's a bit of a religious individual, examine the house, for clues.
Check the various pieces in the main room (walls and a table), go to his room, check out his bed, nightstand and dresser. His bathroom and his kitchen. Head back into the main room and Nathaniel will return. After a few questions, he'll accuse Blake of being the Anti-Christ and point a gun at him.
Jayden will pull out his firearm, simply shoot Nathaniel and you'll earn this trophy. Not shooting him will earn you the 'Self Control' trophy.