In the fourteenth episode of the second season, why did the substitute teacher kill 2 out of the 4 teenagers that invoked her in the forest? And why did she kill the PTA worshipers?
She killed the PTC worshipers because they lost their faith. One of them said:
He [Jim Ausbury] had no real faith, no devotion. He was punished for his doubts. We have to act. Or the same thing will happen to us. If it's not already too late.
After they kill themselves, it cuts to Mrs. Paddock, who says:
You're right. It is already too late.
Why she picked the two teenagers she killed is a bit harder to explain, but if I were to guess:
- Andrea didn't get killed because she recited a Hail Mary while running away.
- Jerry didn't get killed because he was the one who called her in the first place.
These could've given them protection. So by elimination, she killed the other two.