@Tim_Eagon@Da_Gut Watching them on Peacock, I think a couple of them even had the general ABC mystery-of-the-week intro which threw us for a loop when we first saw it.
Richard Levinson & William Link created and wrote most of Columbo. The two of them plus Peter Fischer created Murder She Wrote, although the two of them didn't really write any, only came up with the concept while Peter Fischer and a bunch of rotating writers did the writing (including J. Michael Straczynski of Babylon 5 fame).