I suspect that a lot of the details you're wondering about will quickly emerge in the discussion with Rolf, since (1) our opinions are widely separated, which seems to imply very different-looking calculations, with substantial inferential gaps to be bridged, and (2) that discussion is just getting started.

That said, I'm not sure which missing steps you consider the most important. A very short case summary from my point of view would be something like "student killed by burglar; housemate and boyfriend blamed before burglar discovered; after catching burglar, police filter evidence to fit three-person theory instead of dropping initial idea." Is that helpful at all?