Two Criminals but one death penalty

Its kinda funny how Poncelet and his buddy both killed the couple but people wanted only Poncelet dead. Throughout the movie, people were only pushing for the death penalty on Poncelet. Its as if they agreed with the legal system and excused Poncelet's buddy because he had a more reasonable lawyer even though they did the same exact crime. I feel as if this happens everywhere and not only in the movie. People sway with their words. As long as it sounds reasonable, it does not have to be true.