It was the home of The Trinity Killer and his family
4105 Parkview Drive
A small wooden table holds a whiskey bottle, a pitcher of water, two glasses, and two framed black-and-white photographs: one of a young girl, and the other of a happy couple. Arthur Mitchell places a floral urn in the table’s center. He takes out a small glass vial and pours its ashy contents into the urn, replacing the lid. He sits down in one of two chairs and pours a glass of whiskey, then a glass of water. He pushes the whiskey towards the empty chair, picks up the glass of water, and says “Drink up,” clinking the whiskey glass with his own. “You’re next.”
After The Trinity Killer bludgeons a man to death, Dexter follows him home. He is astonished to discover that he has a wife and two children, and wonders how he manages his cover life.
After he learned Trinity’s name, which was Arthur Mitchell, Dexter delayed killing him because he wanted to know more about him. He found an opportunity when he assisted Arthur with building a house at a Four Walls One Heart site. Dexter purposely sliced his hand so that Arthur would take him into his house to apply first aid. While inside, Dexter discovered that the wall plaques were Arthur's trophies. Also, Dexter felt Arthur's wrath when he picked up the urn containing the ashes of his sister, Vera.
Arthur worked on making a homemade coffin in his garage, after he took a wary Dexter into the woods to help him cut down a tree.
After he finished his coffin, Arthur prayed over it. Dexter parked in front of Arthur's house and approached the family, who were then all outside. They greeted him cheerfully, but soon Arthur began to criticize Jonah for the way he was polishing the car, and his daughter for how she was watering the flowers. Dexter learned that Arthur was planning a trip to Tampa the following day and he developed a scheme to join him. Later, Arthur was seen in his workshop pouring Vera’s ashes into a small jar.
From his car, Dexter watched Jonah being berated by Arthur and drive away in his father’s car. He followed Jonah and ended up agreeing to protect him by attending Thanksgiving dinner at the Mitchell house the next day. Dexter realized how abusive Arthur was when he deliberately broke Jonah’s finger, and discovered the locks on his daughter’s bedroom door and window. While at the dinner table, Dexter observed more of Arthur's cruel behavior towards his family. Jonah exploded with anger, and Arthur attacked him. This almost caused Dexter to kill Arthur (before his wife intervened).
Dexter went to the Mitchell house and asked Jonah to check his father's computer and journals to help him find Arthur, who was staying in a hotel.
While no one was at home, Dexter broke into the Mitchell house and stole Arthur’s toothbrush, razor, comb, and hairbrush brush. His plan was to plant Arthur’s DNA in Stan Beaudry's house and truck in order to frame him as Trinity. Looking into the bedroom mirror, Dexter realized that he was juggling a lot - blood tech, husband, father, serial killer, and extortionist
Knowing that his cover was blown, Trinity briefly returned home to demand money from his family. Then he disappeared again. Dexter showed up to inquire about Arthur. While he was there, a S.W.A.T. team smashed down the front door in a raid. Dexter quickly hid in the garage, afterwards pretending that he was there to do forensics. Debra Morgan was at the scene and informed Dexter that she had found out that The Ice Truck Killer was Dexter’s brother.