Who does Quinn tell his secret to? Why does he confide in this person?

Quinn tells Jill his secret.... that he saw the entire episode, as it played out at Jerry's. In my opinion, he chooses Jill mainly because she is there, as he avoids having to interact with Paul. She is also closely tied to the incident, as her father is the officer in question, and yet, she doesn't side with her father..... she remains objective and true to her beliefs.