It comes out in detail later, so it's not a huge spoiler. Jeff was in a fight in sixth grade, Mr. Turner, his teacher tried to break up the fight. Jeff didn't realize who was pulling him away, turned around and punched the teacher, breaking his nose. He was expelled for three years.
Yes, chapter fourteen is in progress. I'm not sure how many more chapters there will be after that, but I do have a couple open plot points I'm working. So, we're probably less than halfway through.