- "A soldier's way saves the day!"
- ―Mark Rumsfield.
Mark Rumsfield is the third protagonist of the film.
He is portrayed by Bruce Dern.
He joins Ray and Art to help find out if the Klopeks are murderers. After spying on the Klopeks one rainy night, he digs into a garbage truck with Art to see if there were bones inside the bags. Later after he and Art left a note on the Klopeks' door steps and ran, he and Ray went with their wives into the Klopeks house for a greeting.
Next day while Ray and Art investigate the Klopeks' property, he was on the lookout on the neighborhood as Ricky, Steve, Gail, and other teenagers tick him off. Later after Ray and Ricky exposed the Klopeks to the authorities, he restrains Hans and turns him over to the cops and in the end, he, Ray and Art were all agreed with the truth about the Klopeks and went on vacation to their daily lives.