A while back ago me and two of my friends found a site that had all the answer keys to everything in our class. Our teacher found out, but only after the site was taken down, which was only up for a couple weeks (last semester). I have been called in this last week because now there is a answer key book missing, and everyone thinks it is me. The lady said that I "could give it back now for no punishment," but I don't have any idea who has it. They said if they don't get it back by the end of the year, they will investigate and the suspect will drop/fail the class. How should I deal with this? Do they have to have physical evidence or can they get me on word of mouth?