i ditto roger stanford. he had already killed his parents, and i suspect he would have gone on to other victims. that manic presentation is pretty desperate and psycho.

think ruth lytton was pretty whacked out crazy, growing up in that family. even if she didn't seem desperate, she was certainly psycho.

and i am also spooked by eric mason--systematically murdering his wife, his friend, and then putting his hands around joanne nichols's neck, too. i always wonder why she didn't tell columbo that.

I would say that Vivian Dimitri takes top prize on this one. Emmet Clayton from "The Most Dangerous Match" is right up there, too. Beth Chadwick, "Lady In Waiting" is pretty nutty also. Roger Stanford definitely went big time nutso in the concluding moments of "Short Fuse". Up to that point, thought, he wasn't all THAT much off his rocker.

I think the MOST crazed psycho of all was the person who gave the green-light to go ahead with the "No Time To Die" episode.

Headache, I couldn't agree with you more. That episode doesn't even warrant a review.

My vote as most psycho goes to Leslie
Williams in "Ramson for a Dead Man". Her husband did everything for her, got her a good law practice, gave up his seat on the State Supreme Court, and even after she made her demands that he let her live a separate life we see that he still maintained an apparently cordial relationship with her, she cold-bloodedly kills him. I am surprised she didn't get rid of her step-daughter when she started threatening her.
In fact, at the end, Columbo basically tells here this when he says that she "has no concience". (What is odd is that Adrian Carcini is somewhat similar, but Columbo stays friendly with him to the end)

My nominations would be Basehart and Blackman in Dagger of the Mind.

Whilst the initial 'murder' is more an accident, they kill Wilfred Hyde White in cold blood, and Basehart is clearly losing his grip on reality by the end of the episode.

I agree strongly with Vivian Dmitri of "Rest in Peace, Mrs. Columbo" and Eric Mason of "How to Dial a Murder."

Also, let's not forget Justin Rowe of "Columbo Goes to College." His father drove him crazy.

Abigail Mitchell, while not really "psycho," is pretty scary when she says to Edmund, as she is slamming the safe on him, "Do you really think I didn't know?!"