Dexter (episode)
Dexter is contacted by his foster sister Debra (Jennifer Carpenter), a vice officer in the Miami Metro Police Department. Dexter, a blood spatter analyst for the department, assists Debra in investigating an apparent serial killer targeting prostitutes. Dexter examines the latest victim and is shocked to find no trace of blood on the dismembered corpse. At the police station, Dexter discusses another murder case being handled by James Doakes (Erik King), a detective who dislikes him. Later, Dexter watches Jamie Jaworski, a murderer who escaped justice due to a faulty warrant, and breaks into his home to find evidence. Once he confirms that Jaworski is guilty, Dexter meets with his girlfriend Rita Bennett (Julie Benz), a former victim of domestic abuse victim; Rita has two young children, Astor and Cody. While on a date with Rita, Dexter finds another murder scene with no traces of blood, this time with the victim's head missing. Dexter theorizes that the killer murders his victims in extreme cold, explaining the absence of blood, and might be using a stolen refrigerated truck. Dexter allows Debra to pitch the theory, but their superior officer, Lt. María LaGuerta (Lauren Vélez), dismisses it.
Dexter (season 4)
Dexter learns of Lundy's analysis, steals his records, and uses his own skills to sneak into the building and catch sight of the Trinity Killer in the act of dispatching his third victim. Dexter follows the killer to his home, and is very surprised to learn that he is Arthur Mitchell: husband and father, deacon at a local church, and leader of the "Four Walls One Heart" homebuilding charity organization. Dexter continues to watch him and comes to admire his ability to balance his killings along with his family and work lives. Using the alias "Kyle Butler", Dexter joins Arthur's church, befriends him, and learns from him how to improve his own relationship with Rita and his family, giving over his condo to Debra while transferring his killing implements into a shed behind their house. Meanwhile, the Miami police learn that the Trinity Killer places a small amount of cremation ashes at each murder scene, and identify that Trinity and the ash share similar genetics but otherwise cannot match Trinity to any criminal records.