An Unhealthy Attachment - A Father McAllister Mystery, #1

Question: What could possibly scare an exorcist? Answer: A school filled with teenage girls, a murdered co-worker, and a demonic attachment that refuses to leave.  After the exorcism in Cherry Valley goes terribly wrong, Father Gerald "Mac" McAllister is left with bad memories and a secret he doesn't dare reveal--a demonic attachment that he can't seem to banish. Pulled off his exorcist duties, McAllister has been reassigned to provide religious instruction at an all-girl high school under the watchful eye of Mother Margaret Dunnahoo.
If life isn't complicated enough, the priest stumbles across the murdered corpse of the school's art instructor during Open House Weekend.  McAllister can't decide which worries him most: the nonexistent spiritual lives of his teenage students. the suspicious lead detective, or the increasingly dangerous demon. Something is bound to give, and when it does, McAllister fears all Hell will break loose.