I remember seeing the pre-series TV-movie "Diagnosis of Murder" in 1992, but I didn't watch the Diagnosis Murder TV series until the fall of 1997 (as it was starting its fifth season), when Robert Stack made a guest appearance in the episode "Open and Shut." After that, I didn't watch the show again until January of 1998. That was when I finally started watching it on a regular basis.
Considering the fact that Diagnosis Murder mainly appeals to senior audiences, I joke at the idea of being one of the few twentysomethings who watches it. Nonetheless, it is entertaining. In addition, I consider it to be the most underrated 'whodunit' series, and one of the most underrated TV shows in general.
However, the show's most common error is that many murder victims are declared dead literally seconds after they collapse. In other words, there is little that is done to try and revive them. But that isn't always the case. Sometimes, our heroes make some effort to save them until it becomes impossible to do so.
One interesting piece of trivia is that Diagnosis Murder, which has been on for eight years, has outlasted Dick Van Dyke's other show (The Dick Van Dyke Show), which lasted an impressive five years.
With son Barry Van Dyke as Dr. Mark Sloan's son Steve comes a major advantage: if Barry "mistakenly" calls his father dad while playing their respective roles, then they at least know that it's not a mistake at all. Get it?