Thanks for the interesting question, and good luck with your Columbo story.

While I can't answer your question as to who ultimately owns the Columbo character or let's say the "book-rights" (as opposed to who owns the copyrights to individual episodes and books already out there), I can tell you that one of Columbo's creators, Bill Link, published a short-story Columbo book 4 years ago ("The Columbo Collection") with Crippen & Landru Publishers. And I think he might be hoping to publish a follow-up with more new Columbo stories, so Link's own rights, which I assume are clear, may well still be tied to Crippen & Landru.

So while I don't know, I am doubtful that "Columbo book rights" are a sort of free-agent legal entity at this point.

Unless you are determined to put out a hard-copy book (and if that is your dream, I respect it), I would be inclined to second Pete's suggestion that you consider contacting Martin Ross' Columbo fan-fiction site at planetpreset. As far as I know it is (like this site) a nonprofit endeavor for the enjoyment of fans, but you would find your work online in the company of some very excellent writers and creative works by great fans of Columbo.

Again, good luck!

Have you thought about an e-book? Those are becoming increasingly popular and you might be able to negotiate an agreement with Amazon? Just a thought!

I don't want to deviate from the topic here, but just so that "Bryce" doesn't keep using this thread for his playing around, I would like to state right now that, to avoid any confusion, I myself will not post again in this particular thread. While "Bryce's" previous two comments might have legitimacy in terms of content (although I don't really know about those matters enough to judge myself), it's obvious from comments he's made on other threads in the past that he's simply fooling around for his own amusement, and is not at all sincere in whatever seemingly benign statements/suggestions he makes. Apparently his repertoire is wearing quite thin, and he hasn't any choice anymore but to make brief, seemingly well-intentioned comments under my name simply to confuse, if not offend.
I apologize for this break in the topic, but now, at least, I don't think there will be any more of these disingenuous comments being made on this thread. And again, Kai, I look forward to reading your story, in whatever form it ultimately takes.

An interesting suggestion, Bryce (and/or "Bryce" -- I really don't care, as long as either of you acts civil here). I have noticed a few recent Columbo-themed e-books on Amazon, and even bought one of them. (It was ...OK.) They are a fan's ruminations about the episodes, basically a form of literary criticism, which might be in a different legal category than an original story using the character. But, I'm guessing (just guessing) that Amazon could vet that legal issue. So I think it's a good alternative idea worth pursuing.