 Despite Dexter's efforts, Debra and a former informant locate Laura's house, which ultimately links Dexter to Laura, and to Brian.Brian Moser (alias Rudy Cooper, moniker The Ice Truck Killer) is Dexter's biological older brother and the main antagonist of the first season.As children, both brothers witnessed the chainsaw murder of their mother, Laura, and afterward were left for two days with her body in a shipping container until the police found them.