In In Cold Blood, Capote portrays Dick Hickock as a cold-blooded mastermind of the killings of the Clutter family, while Perry Smith is the vulnerable sidekick who goes along with Dick. While Dick has a solid family and is motivated, in Capote's account, by sociopathy, Perry is a more sympathetic character, who goes along with Dick to find acceptance.

For example, Capote writes the following about Dick:

"Dick became convinced that Perry was that rarity, 'a natural killer'—absolutely sane, but conscienceless, and capable of dealing, with or without motive, the coldest-blooded deathblows. It was Dick’s theory that such a gift could, under his supervision, be profitably exploited."

In other words, Dick tries to manipulate and exploit Perry into carrying out the murders. Dick falsely believes that Perry killed a black man, but this is only a lie Perry tells Dick to gain Dick's admiration. Dick is portrayed as a coldblooded manipulator and Perry as his victim. 

Perry is also portrayed as someone deserving of sympathy because he shows far more remorse about the crimes than Dick does. For example, Perry says to Dick, “Know what I think?...I think there must be something wrong with us. To do what we did.” However, Dick denies that there is anything wrong with him and maintains that he is completely normal. In addition, Dick shows no remorse whatsoever for having committed the murders.

Capote also relates Perry's tragic childhood, during which he was raised by an alcoholic mother. He writes of Perry: 

"And, indeed, over the course of the next three years Perry had on several occasions run off, set out to find his lost father, for he had lost his mother as well, learned to 'despise' her; liquor had blurred the face, swollen the figure of the once sinewy, limber Cherokee girl, had 'soured her soul,' honed her tongue to the wickedest point."

Like Capote himself, Perry is the son of an alcoholic mother who turned distant and mean by drink. Perry's dad leaves him for a while, and Perry is raised without parental guidance, while Dick has parents. Perry is portrayed throughout the novel as a victim of abuse, someone who allows himself to be used for bad ends. Dick, on the other hand, comes across only as a sociopathic killer.