Cooper was an ex-convict.
When he was sent to Checkley's World in 2385, he was assigned to sanitary inspection duties. After Sheldukher had stolen Project FXX Q84, wiped the computer files and killed the project director Dr Pethering, Cooper and Yanos were sent into the laboratory to see what could be salvaged. When one of Pethering's surviving experiments attacked him, Yanos let him die since the Board that ran the planet had told them they were less valuable than anything that remained of the research. He did not blame Yanos, since no one disobeyed the Board. (PROSE: Prelude The Highest Science)