Officer Debra Morgan hears the term "cell crystallization" from the coroner in regards to the neck of the headless Fountain Victim. After bouncing the idea off her adopted brother Dexter Morgan, they determine that a "Refrigerated Truck" was the mobile way to keep the victims in cold storage.
Dexter encounters this truck as he returns from claiming the life of Jamie Jaworski. He follows it to a dead end, and the driver makes a U-turn. The unknown truck driver flashes his high beams, and tosses the head of his previous victim out of the window. It smacks against the windshield of Dexter's car, after which the truck driver takes off. The police are called to the scene and Dexter is questioned about what happened.
The next day, the truck is found parked in public with the refrigeration compartment left on. When the Miami Metro Homicide team arrives, they open the back door and look inside. They find a large ice block with the fingertips of one hand frozen neatly in the middle (each fingernail colored a different color).
The truck is later taken apart by investigators, but Dexter and Debra state that this guy is too careful to leave a single fiber that could be traced to him. The truck, or parts of it, were likely kept for evidence.
Due to the discovery of this truck, the killer is aptly dubbed The Ice Truck Killer (or ITK).
The killer uses the blood of his victims to create a crime scene in the Marina View Hotel.
It's revealed that the killer stored the blood of his victims in a built-in freezer located inside his apartment.
- The Truck originally belonged to a company named Miami Chills Ice Refrigerated Delivery, before Brian Moser stole it for his use in Miami. The Truck's original purpose was to deliver Cubed Ice to locations as per the company's contract.
- In the series finale, Oliver Saxon walks past an ice truck owned by Miami Chills Refrigerated Delivery, the same company that owned the truck used by Brian Moser, the Ice Truck Killer. ("Remember the Monsters?")