S12, E8: An apartment building, under construction at the former site of a well-liked community park, is ablaze. The charred naked body of a woman is found in one of the back apartments. Arson is suspected because of the chemicals found at the scene. Conventional wisdom is the arsonist didn't know someone was in the building, but now this is a murder investigation. It takes awhile, but they finally ID the victim - Karen Fried, a local elementary school teacher. She was last seen with Eric Shollar (Michael Leydon Campbell), the father of one of her students, but he's married and hesitant to talk to the cops when they approach him at home. Eric admits that he and Karen were having an affair and he brought her to the building under construction. He claims she was waiting for him while he ran out to buy condoms and the building blew before he got back.