Did the murder trial going on in the Cable Guy have anything to do with Jim Carrey's character? If not then was it just for world-building?

In the film The Cable Guy, we see the ongoing story of the murder trial of Stan Sweet, a person who is alleged to have murdered his identical twin brother Sam Sweet. The identical twins are both played by Ben Stiller, who also directed the film itself.

Often in films you might have a character or ongoing back plot that helps tie the film together. Otherwise sometimes it is to much like a collection of scenes. Even if their are good plots and scenes a plenty, you still need something going on in the background to make it all work.

In Caddyshack, it's the groundskeeper and the Gopher. You keep following their story in the background, until the groundskeeper blows the place up to kill him, and then it merges into the main story for the big finale.

In 12 Monkeys, it is the missing kid that is constantly talked about, and is key to Bruce Willis character proving he is from the future.

In The Cable Guy, the trial of Stan Sweet is largely played for laughs, like the voice recording that they play at his trial, or the silly Made for TV film staring Eric Roberts in both roles, and it just kind of gets referred to here and there on TV as the main film moves along, but then, in the big finale, it moves to the forefront with The Cable Guy trying to die, and kill TV at the same time, but while failing to die, does in fact kill the transmission of everyone's TV, right at the big reveal of if Stan Sweet is found guilty or not.

So what are they trying to say with all of this?

Probably that we are way to obsessed with TV, and reality TV (TV trials in the 90's, such as OJ Simpsons), and instead should focus more on other things, such as book and relationships. The Cable Guy after all tells us that he like so many was raised not by his father, but by father knows best and that his friends were largely the characters on TV. He has come to the conclusion that it is now his place to so much, provide TV, but to end it, and thus through his death, save society from the very thing that has made him the way he is.

On an ironic note, some of those who lose their TV service are his "preferred customers".

The trial itself is largely about two different trials. One, the media frenzy and hysteria not only over the OJ Simpson trial, but the 1995 verdict as well. Everyone was anxiously awaiting the verdict and time itself seemed to stop when it was finally announced. The second trail parodied is the Lyle and Erik Menendez brothers who were in 1994, convicted of murdering their parents. It is clear that he is trying to look like them with the way he is dressed. In fact if you pull up their pictures, he could have been their third brother. His phone call is also a farcical take on the Menedez brothers 911 phone call as well.