It doesn’t have anymore info that the postcard they sent out except that it looks like there are 2 charges of the rape there with the level 3 specification. I have his name and address and all of that.
Ok, good. Knowing his name is an important first step. Start googling him. Use “rape” and “convicted” in quotation marks in your search to try and pull up newspaper articles about the crimes, which may have been committed in another city or state, and to cut down on the number of hits you get of same-named, but unrelated people.
Good luck!