With the addition of the "with limited prosocial emotions" specifier within the diagnosis of conduct disorder (DSM-5) and of conduct-dissocial disorder (ICD-11) to designate those with elevated callous-unemotional traits, the authors examined the role that callous-unemotional traits play in the risk for gun carrying and gun use during a crime in a sample at high risk for gun violence.Male juvenile offenders (N=1,215) from three regions of the United States were assessed after their first arrest and then reassessed every 6 months for 36 months and again at 48 months. Callous-unemotional traits and peer gun carrying and ownership were measured via self-report after the first arrest (i.e., baseline). Gun carrying and use of a gun during a crime were self-reported at all follow-up points.Callous-unemotional traits at baseline increased the frequency of gun carrying and the likelihood of using a gun during a crime across the subsequent 4 years after accounting for other risk factors. Furthermore, callous-unemotional traits moderated the relationship between peer gun carrying and ownership and participant gun carrying, such that only participants low on callous-unemotional traits demonstrated increased gun carrying as a function of their peers' gun carrying and ownership.This study demonstrates the importance of considering callous-unemotional traits in gun violence research both because callous-unemotional traits increase gun carrying and use in adolescents and because the traits may moderate other key risk factors. Notably, the influence of peer gun carrying and ownership may have been underestimated in past research for the majority of adolescents by not considering the moderating influence of callous-unemotional traits.