I’ll take a stab at this.
An episode featuring the murder of the host of The Tonight Show would be a little too much, so let’s say a gruff superintendant and one of his tenants are arguing about the lack of heat in their building when they find the murdered body of Len Jayo, the host of some evening talk show. The dead host had a bitter rivalry with another recently fired talk show host, Brian Conando, who becomes a suspect when it turns out he can’t account for his whereabouts the night of the murder. It’s known he bore a grudge against the dead man and talked about what he would like to do to him. The cops tail him and they grill him. Conando is hiding something.
Interviews (and the autopsy) shows Jayo drank a lot of coffee at a local shop before he was killed. It seems he was supposed to meet with someone but nobody can say who it was. But Conando was seen drinking heavily at a bar across town around the same time, so he can’t be the killer. A young woman was at the bar with him.
Police track down the young woman and find she worked on Conando’s show. She admits they had an inappropriate relationship going back to when she was an assistant. The cops score an interview with the head of the TV network and find that word of this relationship was getting around and was about to become public because it was in the script of the monologue Jayo intended to deliver on his next show. This relationship, and not the network’s contract problems with Len Jayo, is the true reason Brian Conando was fired from his show.
The ex-assistant doesn’t care if her relationship with Conando becomes public, but she tells police her ex-boyfriend, a writer on the Jayo show staff, was furious when he found out she was not only cheating on him, but cheating with someone who competed with his boss.
The boyfriend seems like an obvious suspect. After he is arrested, he admits he was supposed to meet with Jayo for coffee that night. He says he’d had second thoughts about what the monologue might do to his ex-girlfriend’s career and wanted to talk his boss out of delivering it. But he missed the meeting because of a breakdown on the subway. When he arrived, Jayo had already left. His story checks out. But as he is released, he makes a comment in passing about how angry his mother was when she found out about the affair.
As it turns out, the writer’s mother is Mable Jayo, Len Jayo’s wife and agent, Mable. (He is the result of a previous marriage before Mable met her now-deceased husband. The writer and Len had only a professional relationship.) Mable, too, was having an affair with Brian Conando. After writing the un-delivered monologue, Jayo had put two and two together about his wife’s cheating. He confronted her and told her he was divorcing her, and might quit show business altogether. Mable confesses that, rather than see her marriage, reputation, and career go up in smoke, she killed her husband.