The reason I added the question mark is this. Why didn't the most notorious killer ever in Santa Barbara kill either victom when it could have been so easy? And then what about the book deal she wants? And 3rd why did she set herself up to be caught?
I belive the answer is she is not Mr. Yank but a copycat looking for her 15 minutes of fame. They left enough hanging that they could have the real Mr. Yank pop up and kill to show she was a fraud.
As to the funny? It was a bit over the top for what I see as a Murder Mystery with a few moments of humor. Not a comedy with a few serious moments. Real cops would not like the goofyness much I don't think.
But even at that it was a good episode that left Shawn with a problem. Jules finally made a move and he still have some feelings for Abigail.
He could go with Jules and keep it a secret from everyone, even Gus so they could add to the story lines. We'll see.