The part with the camera is in part 15 of 'Truth Be Told'. When I read this post I could have sworn that was the fic described so I checked it out.

But it seems that I do recall reading another fic that is very similar except I think Jennifer actually dies in it and Justin has proof of Craig molesting either him or Molly and he tells Craig he'll use the information to keep him away from Molly. I don't remember the name of the fic or the author unfortunately.