She left the team.JJ told the team that she died from a stab wound that she received earlier in the episode when in reality, she survived and fled. AT the end of the episode JJ is seen giving a set of passports to an unidentified woman.
He gets shot by the one Serial Killer, and it is unknown (to me anyway) whether he survives or not. I hope he does.Also, in previous episodes, he has been blown up.
He left towards the beginning of season 3, the death of his friend in season 2 and the repercussions of Hotch's suspensions all took a toll on him so he wrote Dr. Reid a letter and departed to an...