Ken Thompson is one of Senator Alan Bethlehem's staffers and Cleo Louise Eller's boyfriend. He is present when Bones talks to the Senator and tries to stop her from collecting a chewing gum sample from a bin. He reappears when the police are searching the Senator's house. His tropical fish lead Bones to figure out that he is Cleo's killer. He murdered Cleo because he feared his job was in danger because of her when she revealed she was pregnant. He also covered up her murder by covering the blood covered cement floor with floor tiling. When he tries to set Bones on fire, she shoots him in the leg and is arrested. He later receives the life in prison penalty for her murder, and attempt to destroy evidence.
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