Using first-hand accounts from many sources, Capote pieces together a story. It begins the day before the murders by introducing the Clutter family, the soon-to-be murderers Perry and Dick, and townspeople who knew and associated with the Clutter family. The first section, The Last to See Them Alive, is an eerie one, quickly fleshing out the quiet lives of a family in Holcomb. It's impressive that by the end of the section when the crime finally happens, that you feel a loss. But the personalities are described so colorfully, their presence is felt beyond the 70 pages they're alive.
The second section, Persons Unknown, sketches out the investigation of the Kansas Bureau of Investigation headed up by Al Dewey. Incredibly, regular viewing of procedural television shows didn't diluted the brilliant and brief rendering of an investigation in this novel. In a few of the interrogation scenes, I could imagine David Boreanaz or Mariska Hargitay leaning over a table staring at the criminal in the eyes, but the character development of the criminals in In Cold Blood was deeper due mostly to the fact that the investigation took more than 42 minutes to solve.
Answer, part III, is a slow build to finally catching Perry and Dick and getting the solution of what really happened the terrible night of the murder since that's left a mystery to even the men investigating the crime until they final get the story out of the men. The fourth part, The Corner, is the most unique touch of the novel. It takes time to follow through with Perry and Dick to the bitter end with their experiences on death row. This includes capturing the personalities of fellow death row inmates, Perry's withdrawal, and Dick's need to appeal the trial several times. In the end, it takes 5 years for the men to finally be hung after conviction.
Certainly, the novel is detailed, but the descriptions are so concise, it never feels meandering or like a textbook. The novel format even allows for some character arcs to take place with vignettes defining weeks or months of time. In this way, the novel felt cinematic, with brief chapters that could easily be scenes in a movie or television show. But the richly described inner life would be missed in a film medium. Capote did his homework on this novel, taking him 6 years to complete, and you can tell from the level of detail and beautifully written descriptions. Most impressive, though, is that In Cold Blood manages to draw out human characteristics out of all the people involved, no matter how minor. A fascinating read.