For me it has to be the plunger wine bottle opener that brings down Mr Paul Gerrard. I can never figure out how Paul managed to get back into the crime scene and swap his opener. It just seems strange the way all of the openers were tested and forensics found nothing. I can't see how no trace of poison was left inside.

This may be a bit off base but in Murder by the Book Columbo would have had to get a search warrant to search Franklins bank records. Wonder what the probable cause was for that. ??

Good point.

Once in a great while you notice the opposite thing, where something that SHOULD be a clue gets overlooked (though I guess sometimes that's because of editing). It's always bothered me slightly that Adrian Carsini buys a $5,000 bottle of wine, knowing that his $5,000 check to Ric won't be cashed. It's too bad that Columbo isn't shown finding out about that - even though he finds out that a bottle of wine can go for that price, I don't think he learns about that particular one. Or does he?

Grant i agree. while Carsini admits to spending that much on one bottle Columbo appears to not discover which bottle is worth 5G.

Good point. Along those lines (things that should have been clues), I always think of "A Friend in Deed."

Hugh shows up at the club, clearly nervous or upset, and pulls the police commissioner away from the gaming table to have an urgent private conversation. Later that day, his wife is found murdered. The murder is important enough for the police commissioner to go on television talking about it, yet somehow nobody remembers or reports that strange meeting between the murder victim's husband and the police commissioner on the very day she was murdered.

In reference to "A Friend in Deed," who is Hugh's wife. One website that I saw, asked that question.

I found the cheese clue in "Agenda for Murder" to be pretty strange. I wonder that would hold up in court?