A Friend in Deed is the quintessential Columbo (the hallmark of the entire series), and since I've waxed over every reason why in this forum at least 100 times, that's all I have to say about it.

Can someone explain to me why Halperin thinks changing Janet Caldwell's clothes somehow gives Hugh Caldwell an alibi? I mean she could have changed her clothes prior to him murdering her. Why didn't Halperin just have Hugh pretend she was watching tv when she called?
The only thing I don't like in this episode is that Columbo doesn't seem the slightest bit nervous arresting his boss, nor does he seem surprised when he figures out the Commish is guilty. I have to assume that Halperin had a sleazy reputation, since even Hugh Caldwell knew Halperin would cover up for him. That's a lot to ask of your neighbor.

We never hear Halperin ask for Columbo on the telephone after Janet Caldwell's murder. In fact, we hear him ask for a patrol car to check out the Caldwell house and then we see Halperin hang up the phone. He never asked for Columbo.
Later, Columbo asks Halperin why he specifically called him the night of Janet's murder, since the robber had never hurt anyone before. Sloppy!
I wonder if they changed the story to provide Columbo with another clue.

Agreed. I used to watch that episode over and over. It's really good! As of right now, I am watching Colombo almost every night, especially before going to bed.