The killer had some kind of fantasy (or wants people to think that) about being a crusading Knight Templar, driving the Muslims out of Christendom. But playing dress-up, then killing a bunch of teenagers at camp, is profoundly unchristian, and doesn’t make you any kind of knight. It makes you a contemptible weirdo, and a murderer.
Cain said to his brother Abel, “Let us go out in the field.” When they were in the field, Cain attacked his brother Abel and killed him. Then the LORD asked Cain, “Where is your brother Abel?” He answered, “I do not know. Am I my brother’s keeper?” The LORD then said: “What have you done! Listen: your brother’s blood cries out to me from the soil!”
Hit the gym, tan, and apply light make-up before the professional photo session if you want. The blood of the people you murdered will still cry out from the ground.