I think its time to take this to the next step, take every email, every receipt, and go get a lawyer. Do NOT threaten him, he doesn't have much of a case for himself, so don't give him one.
The court stuff takes a long time, my truck was vandalized when i was in highschool, the guy told a bunch of people he was going to do it, (it was home coming, and allot of people go around pulling pranks on eachother). he also had three felony's on his record and was not yet 18. He took all the lugnuts of my rear passenger tire, and the tire came off in the parking lot, causing $2,300 in body damage to my truck, and also twisted the frame. I had bought it a month earlier.
i went with the county attorney, bad idea, he got his own lawyer, my guy didn't really care about the case, never told me what was going on, and 6 months later when we finally go to court. his lawyer had 2 witnesses that the county attorney approved of, what do you know they are both his friends, and one even said that i offered them $50 to testify against there friend. and his lawyer started asking me questions like where were you, and did you ever pay some one to remove your lugnuts, and how do we know you were at the game. my answer was because i played, and then he asks but did you play the whole time. long ass story short, he got off, cuz they said it was all circumstantial evidence.
basically all i can say is get your own lawyer, a good one is well worth it. but be ready for 6 to 8 months of bullshit.