In engineering lingo, KISS means "keep it simple, stupid." It's a mantra that we as criminal defense attorneys need to keep in mind when preparing our cases for trial.
As I was watching a show on Discovery Channel about natural disasters, I saw an interview with an engineer from Iowa State University who had constructed a tornado simulator. The device, which can simulate tornados with winds in excess of 300 mph, only has four components.
A good story only needs a protagonist, an antagonist and an event. Too many characters, too many subplots and too many twists will weigh down a book or a movie - rendering it unreadable or unwatchable. The books and movies we remember are very simple stories.
Jurors don't have enough time or energy to absorb a complex story. They have a host of other things on their minds such as the inconvenience of serving on a jury, a project at work, problems at home, children and the like. Don't be guilty of confusing the jury, let the prosecutor spin a complex yarn and lose the panel.
Don't overthink your case. Boil it down to its essential elements and present it to the jury in a way in which they can follow the story. If you can describe your case within the construct of a story to a stranger, or a person with no knowledge of the case, then you're on the right track.