Great investigative fun! I discovered a bug, though, that really derailed my playthrough. After getting back the autopsy information, and checking the relevant book for relevant information, I went to ask Margo about snakes a second time, and the page was blank. Like, not even displaying the previously-discussed information. Completely blank. Definitely not supposed to be that way - and I suspect there would have been new questions there, for all the obvious reasons, and may have even unlocked some further interactions. It seemed like a real roadblock to getting the last bits of information necessary to fully solve the case.