"Karl" dated one of Paige's charges and presumably was killed by Zankou. When Paige met Karl, she instantly got a bad vibe from him, supposed by the fact that he was violent to his girlfriend. It was soon revealed that he was in fact Zankou.
When Joanna found out, he killed her and left her dead body for Paige to find. It is believed that Zankou killed and replaced the real Karl around the time Joanna became Paige's charge, as they had likely been dating for some time.
"Karl" appeared in a total of 1 episode throughout the course of the series.
- Season 7
- Death Becomes Them