His parents pimped him to various pedophiles in his childhood. That and later incident in which they were killed (possibly by him) made him an unstable person with blackouts. During this blackouts he was hypnotized and unwittingly used by Cult of Moloch, probably posessed by Moloch himself.
Jerry is a professor at the same college where Ariel Goldman, one of the two female victims attented. He is the primary suspect after Professor Wilkins tips Deborah and Dexter about Jerry's past altercations with the female student. Jerry states he had nothing to do with Ariel, stating she was the one that ripped her own shirt, after he did not accept her sexual favors in exchange of a good grade. Deborah does not believe his version, not accepting he could say no to a young woman as Ariel. Though convincing, Deborah still proceeds to arrest Jerry and heads to the Miami Police Department for interrogation, not before the latter tried to escape, however he was stopped by Dexter.
Deborah interrogates Halpern back at the HQ with no avail, with Halpern remarking that everything he remembers about the crime scene feels like a dream, as he is not capable of such things.
It is implied that he burned down a house of his parents, killing them.