being taken out of his home by the police when they uncover that Arthur is Trinity. In season 5, he is seen in a store where Quinn approaches him with a composite sketch of Kyle Butler which resembles Dexter. Before Jonah can give him an answer of whether the picture is Kyle Butler/Dexter or not, Quinn is taken into custody by an FBI agent in charge of guarding Jonah while in witness protection. In season 6, he reappears in the episode "Nebraska" as the sole survivor of his family who has been reportedly murdered by the Trinity Killer. While Dexter suspects that Jonah was the perpetrator, with supporting evidence, Jonah's guilt emerges in a confrontation which shows that he killed his mother for instigating his sister's suicide. No longer truly fitting the Code of Harry, Dexter tells him to forgive himself and returns to Miami. Rebecca Mitchell Vanessa Marano Rebecca Mitchell is the daughter of Arthur and Sally. Though she is a 15-year-old teenager, her bedroom resembles that of a young child. After running away once, Arthur now has locks on the outside of the door and on the windows. Arthur often calls her "Vera", the name of his deceased sister. When Dexter asks her about this and tries to console her, she asks him to take her away, saying she would do "anything", implying she will give him sexual favors to do so (which Dexter flatly refuses). Both Becca and her mother believe he will take Becca up on her offer, however, the latter hopes that Dexter will not allow Arthur to find out. She is last seen in tears being taken out of her home by the police when they uncover that Arthur is Trinity. A year later, due to the unstable rantings of her mother, Rebecca commits suicide in a way similar to the second victim in her father's cycle of kills. This discovery prompts Dexter to investigate. Additional characters, introduced in season 5 Lumen Pierce Julia Stiles Lumen Pierce is first seen after witnessing Dexter kill Boyd Fowler, a serial killer who had been keeping her captive. Despite Lumen being a witness to the murder and a clear threat to Dexter, due to her not fitting Dexter's code by being innocent, he is morally obligated to keep her alive and locks her up in a secluded area to give himself time to decide what to do