Mark, I don’t think there’s any real evidence regarding Edmunds guilt. It’s just a backstory to give the the main character a motive to commit murder and thereby enhance the main plot. It’s up to the viewer to decide if the motive is valid. I don’t see any reason why Mark would be innocent because it doesn’t serve the plot and the director showed nothing that would exonerate him.

Columbo mentions that he read the file on the nieces’ murder and it was somewhat inconclusive. Also that Mark must have had a very poor marriage. Other than that we have Abbie’s suspicions.

So I suppose Abbie could be in so much pain that she just blamed Mark. But more likely he killed her. I guess a divorce was too difficult, lol. He certainly couldn’t have expected to inherit. That should have been a red flag when Abbie was so nice to him.

Interesting take, Pete. I just think it has to be more than a coincidence that even in the show, the report showed "inconclusive..." and the show itself left us very little, close to nothing, as far as any real proof that Edmund killed his wife. The writers easily could've given us something more substantial. They could've showed Edmund talking to himself after Abby decided to make him her heir, saying something like, "...just how I planned" or "...thanks Phyllis" with an evil chuckle or smirk. But nope, in fact, they did the opposite. I do really feel that this was to have us viewers not feel overly sympathetic to a 1st degree murderer.

That may be true, that they don't want us too sympathetic, especially after Columbo says how much he likes certain murderers: "Not for what they did, never for that", etc.

I also think that sometimes a write fleshes out a great back story and some studio hack will come in and edit it to shreds. In Murder With Too Many Notes it's so bad that it looks like they ran out of time. The final clue that was supposed to catch Findlay Crawford was from written music that spelled out B-E-C-C-A. And therefore.....? Therefore the episode was over and Crawford asked if any prisons had a good orchestra, lol. IT MADE NO SENSE!

So perhaps Edmund's back story and the niece's death would have been fleshed out more and, for purposes of brevity, they just said she died mysteriously. And Abbie suspects foul play.