Stampler is a 19-year-old altar boy. He appears meek and shy, with a severe stutter. He's attention-starved and lovesick.
When the Archbishop is stabbed, Stampler is found covered in his blood and is arrested. Stampler insists that he's innocent, that he blacked out and woke up covered in blood. It's revealed when intimated or threatened, Stampler flies into a rage, his stutter vanishes and he becomes a violent, possessive, and obsessive sociopath named Roy.