Dieter bore a strong resemblance to the Model 101 Terminator/Infiltrator. Despite this, he was never suspected or accused of its crimes during its initial rampages, as his superiors always knew that he was located elsewhere during the times when the first Terminator's mission to kill Sarah Connor and the second Terminator's mission to protect John Connor.
At the time of his involvement with the Connors, he had retired from active service and lived in Paraguay as a cattle rancher. During a trip into town to recover a package being sent from the United States, Dieter was spotted by Sarah Connor, who was living under the identity of Suzanne Kreiger, the owner of Krieger Trucking. Sarah ran from Dieter, believing him to be a Terminator due to his resemblance to that particular model line.
Despite this rocky start, he developed a friendship with Sarah and her son John. He was cemented as one of their allies when a Terminator was sent to kill both he and the Connors during a dinner hosted at Sarah's ranch — though Sarah originally planned to kill Dieter for fear that he had discovered who she was. He would later assist the Connors against Skynet agents Serena Burns, Alissa, and Clea Bennet.
Dieter then involved in a relationship with Sarah Connor and later became a member of the Resistance. He survived until at least 2029 and presented himself along with Sarah Connor after Kyle Reese was sent back in time to 1984.
- The actor Arnold Schwarzenegger, whose appearance is used as the base for Dieter von Rossbach, is an Austrian and a naturalized U.S. citizen, just like von Rossbach.
- Holmes: "How bad do you expect this thing to get?"
- Dieter: "Bad. Not as bad as it would have been six years ago maybe. But bad. Billions dead. End of civilization as we know it. Possible extinction of the human race."
- Holmes: "I really hope she's crazy, Dieter, if that's an improvement over the original version."
- Dieter: "I wish she was."