The husband is in prison wearing a jump suit, a white dress shirt, and a tie. In jail or prison, no inmate has a tie, belt, or shoe laces. In fact, all items are taken away from prisoners when they are booked.
When Mr. Marko is talking on the telephone with George Mitchell, the columnist, he hangs up the phone while he is still talking to him. Mr. Marko says the words "Be seeing you" as he is placing the receiver in the cradle.
Why didn't Marty's apartment caretaker go to the police about letting Marty back out of his room after his friend Joe had bolted him in for the night to sleep off his bender? Initially, he had no reason to suspect Marty of the crime of murdering a Mavis Marlowe, but he became aware that Marty was a suspect afterwards (and thus Marty's alibi didn't hold). He would not have been complicit in anything more than taking a quarter from Marty to be let out, the little game the two played behind Joe's back.
How can Marty only recognize Kirk's picture (in a framed photo at Christine's home) deep into their "undercover work" together? He never went to the trial (of his ex-wife's murderer)? He never bought a paper, or saw one on a bar top, with Kirk's picture in it the entire duration of a sensational trial? It seems impossible for him to not know that Mr. Marko was not the man tried and convicted of the murder.