Why was Sonny in jail?

Could you please elaborate on the reasons behind Sonny's incarceration? Was it due to a criminal offense, a misunderstanding, or perhaps a violation of some sort? It's intriguing to understand the specific circumstances that led to his detention, as it could provide valuable insight into the complexities of the legal system and the potential challenges faced by individuals within it. Furthermore, knowing the nature of his offense might shed light on any lessons that can be learned from his experience.