Question: what episode of criminal minds does prentiss fake her death?
Answer: Season 6, Episode 18, "Lauren" While the rest of the team mourned the loss of Emily, JJ was later seen meeting a woman in Paris. After providing passports to the mysterious woman, it was clear that Emily—with the help of JJ and Hotch—faked her death in order to hide from Doyle and protect the rest of the team.