Detailed Explanation
Brian Moser, the Ice Truck Killer (also known as the "Refrigerator Truck Killer" or "Prosthetics Killer"), is Dexter's biological brother. Unlike Dexter, Brian was left to witness their mother's brutal murder and subsequent dismemberment, receiving no guidance to channel his trauma. He became a serial killer who murders prostitutes, drains their blood, and leaves their body parts in refrigerated trucks as a twisted way to communicate with and reconnect with his lost brother. Brian infiltrated Dexter's life as "Rudy Cooper," even getting engaged to Dexter's sister Debra, all to reveal their shared past and convince Dexter to embrace his true nature without the constraints of Harry's Code.