Derfler was waiting for his babysitter when he saw his mailman acting odd at a neighbor's house across the street. The postal worker then pulled down his pants.
That's when Derfler starting snapping pictures. The pictures show the postal worker squatting near some bushes and pulling his pants up. Derfler even photographed what was left behind.
"We trust people like the postal service and meter readers and people of that nature," said Derfler. "To come on to our property and to defecate - it's just wrong."
The post office is embarrassed.
"Immediately, the individual was removed from the workroom floor, and they were put on unpaid leave," said Ron Anderson, with the U.S. Postal Service.
The post office hasn't decided whether it will fire the worker. It still needs to complete its investigation into the matter.
"That is something we'll have to find out," Anderson said. "That's a possibility. I don't know what the final outcome will be."
After a KATU News reporter showed Anderson the photographs of the worker, he said it was inappropriate behavior.
"Why an individual like this would ever make a decision to do something that is just beyond common sense and reason, I don't have an explanation for this individual," he said.
Derfler said he hopes it doesn't take the post office long to reach a conclusion.
"I don't know if this is a firing offense or not, but for me, it would be," he said.
Two postal employees, who know the worker, said the man is embarrassed.
Within two blocks from where the incident occurred, there is a public park with porta potties and a store with a public bathroom. It is not known why he didn't go there.