Jerry Orbach appeared as Harry McGraw in quite a few episodes of "Murder, She Wrote" and his character was so popular that he received a spin-off series, "The Law and Harry McGraw". Alas, while he was reasonably popular on "Murder, She Wrote", he wasn't popular enough for his spinoff series to last more than 16 episodes.
Soon after the story begins, Jessica learns that a private investigator working for her was murdered. She naturally wonders if the case she had him working on had anything to do with it, so she contacts his partner, Harry McGraw, to find out more. As for McGraw, he's kind of a jerk and treats Jessica poorly...and in many ways he seem like an old film noir protagonist....hard boiled, cynical and in search of the man who killed his partner (much like Humphrey Bogart in "The Maltese Falcon"). Eventually, McGraw relents in his nastiness enough for him and Jessica to investigate the murder together.
While the mystery might not be one of the best ones on the show so far, it did have very interesting characters and never was dull. Well worth seeing and it makes you want to see more of old Harry.