Apart from LAST SALUTE FOR THE COMMODORE (and in a way DOUBLE SHOCK), the audience knows who the killer is, but which characters would the audience be very tempted to suspect if the show WERE a murder mystery?

One that took me forever to think of is Murcheson in LOVELY BUT LETHAL. What if he found out that Karl stole his formula and also made it look like a failure? Also, he's always been madly in love with Viveca, and he would be helping her also by killing Karl.

Another on is Ned Diamond in FORGOTTEN LADY, who of course actually confesses to the killing. And even though the WAY he says he did it sounds very fishy to Columbo, the MOTIVE he describes makes a good deal of sense.

Another one (though I've already mentioned him) is Lloyd Harrington in TROUBLED WATERS. In spite of how risky murdering Rosanna on the ship would be, he has a perfect motive. Plus, by the time it was made, Dean Stockwell had played a lot of "spooky" characters, so typecasting could also make you suspect him!

How about Kerry Malone in "The Conspirators"? Joe Devlin sent him to follow Mr. Pauley, maybe after finding out Pauley was going to cheat them, Kerry took it upon himself to pay Mr. Pauley in full, as a drunken Irishman once said.

Or "Candidate for Crime". What if Linda Johnson killed Harry Stone for the same reason that Nelson Hayward actually did?

I think the "best" red herring was the one created by Miss Lytton in Old Fashioned.

It was so good that it made all of Columbo's hooks on the case seem almost ridiculous.

I mean, you have a "career" criminal caught in the act of a robbery in a dark museum triggering a double-shooting, all of which makes 100% perfect sense from any reasonable detective's point of view, including ballistics, etc. It all checks out. Yet Columbo uses the freshly-cut hairs on the perp's tee-shirt and newer shoes as some kind of justification for thinking it was all set up?? Further, the lights being turned off would be an entirely reasonable expectation of an actual crime scene that took place during the night hours. Yet Columbo thinks it's odd?? No way on earth this would happen in reality - a detective raising flags over this stuff. It's just too unbelievable to me that they would dig further. Just as his assistant said:

"I have to be honest with you, sir. Everything seems perfectly normal to me. Why does it look peculiar to you?"

Because he was dressed to go somewhere on a plane?? Yeah Lt., not a crazy notion.

"Oh, he was going somewhere, Sergeant. He was going somewhere"

Yeah, Lt.. Who wouldn't be?? lol

Nonetheless, I really do love that episode.

Was it something about both of them being such good shots in the dark.

To some people, Ken Archer in DEATH LENDS A HAND would be a good one, either because Lenore was going back to her husband and he felt rejected, or simply because of his "loose morals," being the kind of golf pro who starts things with his female students. The second thing makes no sense, but people can draw a straight line between something like that and something like murder!

Columbo did keep asking "who turned the lights off", because I think he too realized, that from that distance, no way they could both deliver dual fatal single shots in complete darkness!