Details of Disappearance Zellmer disappeared from Sioux City, Iowa on April 6, 1985. At 5:50 a.m., police found his 1984 Chevrolet Cavalier on the south end of the Veterans Memorial Bridge in South Sioux City, Nebraska. It was unoccupied, with its motor running. When they went to Zellmer's apartment in the 1000 block of Pierce Street, they found it empty with no signs of any disturbance. Investigators searched the Missouri River after Zellmer's disappearance but uncovered no evidence indicating his fate.
Zellmer had been depressed for years before he vanished and his disappearance was investigated as a possible suicide, but he could also have been taken against his will. His case remains unsolved.
- Sioux City Police Department
Updated 2 times since October 12, 2004. Last updated February 2, 2013; details of disappearance updated.