What would a police lieutenant be without a bumbling sergeant to yell at? Sgt. Nelson is Lieutenant Victor Sabian's aide. Nelson is a bit of a klutz and not very bright, But, sometimes Nelson will suprise everyone and come through when needed. He makes up for it by being one of the best shots on the force. Nelson though his own ingenuity was eventually promoted to detective. This character is based on Sgt. Otis from the Old Time Radio show Richard Diamond, Private Detective . Sgt. Nelson is played by M. John.