Mystery solved!
The clues to the mystery are the bag of potatoes, the wig, the rope, and the bloodied oar. And of course, the red herring, which in this case is a literal fish, wrapped in brown paper.
The victim was the psychiatrist, or so Robert George of the SFPD tells us. In a short booklet that comes with the puzzle, he also shares transcripts of his interviews with three suspects, all of whom are obsessed with the movies of the Master of Suspense, Alfred Hitchcock.
Did we solve the crime? Almost. We figured it all out except for the final twist. It was like watching a Hitchcock movie.