What I Tell You Three Times Is False
Written as if from an autobiographical viewpoint, Samuel Holt is also the hero of the book, an ex-cop turned stereotyped-actor who starred in a TV detective show, now solving crimes. This is the third book in the series, after One of Us Is Wrong and I Know a Trick Worth Two of That. There's also a fourth one, The Fourth Dimension Is Death. The books are unfortunately out of print but they're worth looking up in the library, good fast moving plots, a self-effacing hero with a decent sense of humor.
I see a rumor on Amazon that Samuel Holt is also Donald Westlake and my local library does link them together in their catalog, I think I'll check out some of Westlake's books too.