Truman Capote employs two very different writing approaches when describing the Clutter family, who are the innocent victims of Dick and Perry, and when describing Dick and Perry, the perpetrators of the horrific murders.
Capote emphasizes the innocence of the Clutter family by describing their home poetically:
The village of Holcomb stands on the high wheat plains of Western Kansas, a lonesome area that other Kansans call 'out there.'
The descriptive nature of Capote's language in this long, evocative sentence creates a picture in the reader's mind of a lonely and isolated place, one that may not provide protection to the residents of Holcomb. The natural environment is wholesome and unadulterated, which implies a trusting innocence about the Clutters, who choose to live in such a simple landscape despite its isolation.
In contrast, Capote employs shorter phrases, strung together in a punchy style, to describe the two criminals, Dick and Perry. This sentence is long and conversational, full of commas and pauses, so much so that the sentence seems to interrupt itself:
Of course, Dick was very literal-minded, very—he had no understanding of music, poetry—and yet when you got right down to it, Dick's literalness, his pragmatic approach to every subject, was the primary reason Perry had been attracted to him, for it made Dick seem, compared to himself, so authentically tough, invulnerable, 'totally masculine'.
The short phrases separated by commas are almost aggressive in tone, and the phrasing of the sentence is slightly disorganized, just like the men themselves. The reader can almost imagine either Dick or Perry narrating this part of the book himself and getting wrapped up, unhelpfully, in details and nuance.
Capote's ability to change narrative style so effectively may explain the enduring popularity and status of In Cold Blood; the differences in his approaches to the characterization of the Clutters and their killers make for a supremely emotional and memorable reading experience.