Once it starts raining you have access to all the bodies you need on the ship. Rewatch every flashback and take notes. Details really matter, and those flashbacks are crime scenes that need to be studied fully. Pay special attention to clips in quick succession, as a clue from another flashback may show the means of death or the killer.
>Details really matter, and those flashbacks are crime scenes that need to be studied fully.
This is really what the game is all about. It's amazing when you're going through a scene for the 10th time and pick up on a huge clue that's been hiding in plain sight all that time.