Billy Hicks is Matrix's assistant. He has a wide range of duties which range from performing background checks on targets and victims, to roughing up goons, to cleaning up after Matrix's activities. He does whatever is necessary for Matrix to carry out a contract. Though Billy claims he's never killed anyone in his ten year career with the mob, he planned to do away with a reformed mobster, Terry Cox, in the episode FALSE WITNESS. When he found out that Terry named him as part of Cangelosi's men, and that the police was hiding the snitch after staging his death, Billy planned to finish him off with or without Matrix's help.

Billy leads two lives. As a devoted family man with a loving wife named Esther, and as a caring father who plays basketball with his two young sons, the Hicks family think that Billy is a restaurant consultant who boots around in a classic 1967 yellow Mustang. As a member of the mob family, Billy is loyal to Matrix, a man he has known for 15 years. They've helped each other get out of tight situations on several occasions. Most notably, in the episode LOVE KILLS, Billy made the mistake of dumping the body of murdered mob boss for his ex-girlfriend Angela Carlton. But Angela framed him for the murder and his affair with her was blown out in the open, and Matrix had to work fast and hard to clear Billy of the murder. Conversely, when Matrix was also framed by a current love interest for intentionally running over her father with his corvette in the episode TO ERR IS HUMAN, the quick-thinking Billy Hicks found evidence to prove that the victim was already dead when the body was hit by Matrix, hence, clearing his name.