In Chapter 5, after Curley’s wife is found dead, Curley explicitly threatens Lennie. He says something like, "I'll kill the big son-of-a-bitch myself. I'll shoot him in the guts." In other words, Curley vows personal, violent revenge — he intends to find Lennie and kill him himself rather than leave punishment to anyone else.
Why this matters for characterizing Curley:
- Vindictive and violent: The threat shows Curley’s immediate turn to violence as his first response. He wants revenge rather than asking questions or seeking a humane resolution.
- Insecure and pride-driven: Curley’s need to mete out punishment personally is tied to his bruised pride (he’s small, aggressive, and obsessed with proving himself). Taking revenge on Lennie would reassert his dominance after previous humiliations.
- Impulsive and lacking empathy: The language and tone show little concern for motive, context, or mercy; Curley focuses on punishment, not understanding or justice.
- Uses power for personal ends: As the boss’s son, Curley has authority and a gang behind him — his vow signals he will mobilize that authority to get what he wants, regardless of fairness.
- Drives the plot and contrasts characters: Curley’s thirst for violent retribution creates the immediate danger that helps explain George’s later decision to shoot Lennie himself (to spare him from a crueler fate). It contrasts Curley’s brutality with George’s painful mercy.
In short, Curley’s stated intention to "kill" or "shoot" Lennie in Chapter 5 crystallizes him as aggressive, insecure, and vengeful — a character who responds to crisis with violent retribution rather than compassion or reason.