How many people in the prison know the true crime that the fat convict committed?

No one on the plantation knows the true crime that the fat convict committed because he has never told anyone. The fat convict is serving a 100-year sentence for the murder of a gas station attendant, but no one knows for sure if he actually committed the crime. They do know, however, that he was in the stolen car that was seen at the time of the murder, so he was arrested.