In Cold Blood

Dick is in many ways the more evil of the two killers. A head injury early in life led to him adopting more psychopathic tendencies, though his upbringing wasn’t as turbulent as Perry’s. He has an ex-wife whom he claims to love, but she left him when he cheated on her and got another woman pregnant, whom he subsequently married then abandoned. Despite is relatively high IQ, he becomes a creature of impulse, and has little capacity to distinguish right from wrong. This is most evident in the crimes he commits – not only the murder of the Clutters, but his molestation of young girls. Though he is “sincerely ashamed” of this, he is unable to suppress these carnal desires, which is further proof of his diminished psychological capacity. He is apparently only prevented from raping Nancy Clutter by Perry, who detests the idea.

These impulse-control tendencies align with another common psychopathic trait of over-confidence. He regularly dismisses Perry’s concerns about the possibility of getting caught, though there are many flags throughout the novel that Dick is not the criminal mastermind he thinks he is. Rather, Dick is a conscience-less killer, and in many ways a distillation of the most selfish, evil parts of humanity. His relationship with Perry is complicated; the men only share “surface level” similarities with Perry being more artistic and Dick being the “literal minded” one, and at times their personalities clash. Dick had been intrigued by Perry’s claim to have killed a man with a bicycle chain, and once considered Perry “a natural killer – absolutely sane, but conscienceless and capable of dealing, with or without motive, the coldest-blooded deathblows,” though this is not remotely true.

 
Perry would claim in a confession that Dick killed Mrs and Nancy Clutter himself, but he refused to sign his name to verify this, and would instead take the blame for all four deaths, which was the story Dick insisted on (further evidence of his self-interest).

Readers are typically less inclined to empathise with Dick due to his lack of self- reflection. Where Perry is more self-aware and self-critical, Dick’s anarchy and recklessness makes him seem rather impulsive and unlikable.
He is the first of the two to be executed, though more time is devoted to Perry’s hanging, for Dewey considers Dick a “small-time chiseller who got out of his depth, empty and worthless.”