This episode kept me riveted from the "Jessica-and-sidekick-have-car-trouble again" beginning, until the "guess-again-who-dunnit" ending. Again, what I've come to love so much about MSW is Jessica's unintentionally funny ability to solve a crime based on an obtuse, solitary fact that she just happens to know. In this case, what led her to the murder weapon was a very precise, expert knowledge of the ammunition used in a certain type of novelty firearm. When she is questioned about this obscure reference, she mentions modestly and casually, "Oh, I just read it recently in my research." Another Jessica-the-omniscient moment!
There is another how-the-heck-did-Jessica-know-that instance, when she divined that Matt (the suspect) was Professor Caufield's son. While it was obvious that there had been something between Professor Caulfield and Matt's mother when they reconnected in the hotel lobby, Matt's mother had been married previously. Jessica's assumption seemed a bold one to make to both their faces, based solely on her sociology study between the two of them! All in all, this episode contained the key ingredients of a great MSW episode: a despicable bad guy who winds up dead, a local sheriff who scoffs at the idea that this author-dame could possibly know what she is talking about despite her perfect track record in solving murders, and of course, Jessica's supreme ability to pick up on some random knowledge that 99.9% of the rest of the population would never ever know.