Great observations! Like yourself, I only recently noticed the smoke that you referenced in your post! Isn't it great that much time (in my case, years and years) can pass and we just notice something that may have little substance, if not none at all, to the case or scene, but nontheless adds a bit of humor and honestly to the scene!

The San Diego Police Department should have charged Franklin with murder as both murders occured in that jurisdiction.

Thanks. Did not notice that either. Yes, this was out of Columbo's jurisdiction by a hundred plus miles.

Another thing that comes to my mind is how easily the murderer agrees with Columbo at the end, basically agreeing that he is guilty. Considering his demeanor throughout the episode I would think he'd balk and deny everything.

In this episode, like in others, the killer did not have to kill. In it the writing partner / victim does not seem like the kind who is EVER going to mention that the murderer could not write. So why kill him? The murderer could easily have said in interviews that he just did not want to write anymore, said that to anyone. He could have lived comfortably off the royalties without risking a murder conviction. Besides the wife knows the secret and he does not kill her. Perhaps he killed because he was jealous but Columbo does not think that.

(I wonder if the writer of this episode was revealing how they would feel if they were in the same situation - that he would be overwhelmed with some kind of shame and in a sense paranoia, thinking that people were actually going to speculate that he got credit for writing that they did not do. In real life there would not be much discussion if a writer stops writing - few would bother to investigate. Only a writer would think so.)

I am pretty sure the writer of this episode was nominated for an emmy.

I believe you're correct, Ed; Steve Bochco was nominated, but lost to Richard Levinson and William Link for their work on "Death Lends a Hand" (with "Death" being my favorite episode from the first season, I personally agree with that choice, although as far as Bochco's first season work, I actually prefer "Lady in Waiting" over "Murder by the Book").
Those are interesting observations, Irene. I wonder if some of those amusing details were perhaps added by Steven Spielberg in directing it; for me personally, I felt his work with the camera and capturing the mood really overshadows the writing, which, as has been pointed out, had some overlooked elements. I also didn't like the fact that Columbo acted a little too deferential in the episode, with his frequently asking Ken to explain things to him (sometimes with Ken almost cartoonishly mocking Columbo's intelligence, another element I'm not too fond of). Of course, with a great cast, stylish direction and wonderful music all of that recedes from my mind in watching it.
I also want to point out really quickly that there's a dishonest user posting on this topic, for now using the name you see in the above comment ("The Real Bryce"), though that may change to simply "Bryce" if he decides to try to cause confusion in this thread. Again, be sure not to take that name for granted, and I'll keep silent about anything he might try on this thread, so that the real topic here can proceed normally.

Regarding the motive, I believe that it was about the life insurance policy. Remember that Ken spends "like a drunken sailor". With no new books coming it appears that Mrs. Melville will no longer be so kind to him.

Two parts that I love: First is when Ken says about why he drove from San Diego: "When you add up the time traveling to and from the airport, how much time do you really save?". Columbo just looks down and moans something meaning that he is not at all convinced. It takes some of the cockiness out of Ken.

Also when Columbo notices that Ken went through his mail and says something to the effect of: "Oh sure, and bills are very distracting". Two good indicators that Ken was guilty and both translate to real life. Great episode!

I've said it before, but I can never help thinking that Ken could have at least TRIED to find "another" James Ferris. In other words, another writer who cared about the writing itself a lot more than getting the full credit, and who wouldn't mind slipping into the same kind of pattern that he had with James - with the other person doing all or most of the writing and Ken doing almost all of the public stuff.
In fact, it could have been even easier if the other writer were a she instead of a he, someone he could use his Jack Cassidy type charm on to talk her into that kind of arrangement!

While you raise a valid point of discussion, I tend to believe that Franklin didn't want to 'do the work' as one might say and actually find another writing partner. One might argue, of course, that actually committing the murder was, so to speak, more 'work', but Franklin was more caught up with the ego rather than carrying through a plan - as noted with the matchbook notation.

I think there's also the simple matter of Ken's ego and pride over not wanting to ever let it be publicly known that he did no actual writing. It was obvious that was a sore subject with him and that his desire to murder Jim was ultimately rooted in the fact that sooner or later he'd be exposed as someone who never had any real creative talent. With an egotist like Jack Cassidy in the role, it's very easy to believe that pride could motivate a guy like that to commit murder and try to get away with it using the one brilliant creative idea he ever really had (I wish the final episode as aired had made the point that I think the paperback novelization did that the reason why Jim never used Ken's alibi scheme for a Mrs. Melville novel was because it was too good. That he couldn't think of a way Mrs. Melville could break it).

In seeing how Ken and Jim are such polar opposites in personality and lifestyle, it could be speculated that Ken's motive in murdering Jim, besides jealousy and "the ego", as you succinctly put it, "Bryce", was driven by an anger of having had to work with someone for so many years with whom he seemed to share little in common. There's a sense that Ken has distinct personal pleasure in killing Jim, such as when he devilishly raises his glass to "toast" Jim's corpse, or the perpetual smirk he has the whole time he's manipulating Jim's emotions and naivety in preparation for the murder, as though his killing Jim not only satisfies his greed and ego, but also a desire to be relieved of a friendship that had become tiresomely incompatible (that is, in the sense of Ken having to not only maintain the lucrative sham of being a writer, but the far less enjoyable sham of working with and relating to someone wholly devoid of his own ambitions and "values"). Of course, there's nothing explicitly stated or shown within the narrative that indicates Ken was upset with Jim before Jim's decision to write on his own, but again, given their drastically different personalities, I can't imagine that Ken would ever genuinely be interested in a friendship/partnership with Jim, other than what it affords him in fame and wealth.
One of my favorite scenes in the episode is where Ken expresses his contempt for Jim very openly - "Whoever thought that idiot would write it down!" I love how the line leading up to that ("I must have told it to Jim over ... years ago") is said so sentimentally in a way, with the accompanying music eerie and reflective, almost in a seeming attempt to make the viewer think Ken is finally going to show remorse and pity, only to have both he and the music resume their discordant ways.