IntroductionMost people are generally honest, but around 5% of individuals are prolific liars, some of whom lie for fun or no reason. However, developmental research on atypical lying features (e.g., motives, attitudes, inclinations for dishonesty) and the associated traits and negative outcomes is lacking. We examined how psychopathic traits are related to the development of lying trajectories and whether exhibiting atypical lying features during a developmental period when lies tend to decrease in frequency (i.e., adolescence to adulthood) increases the risk for adulthood antisocial behaviors.MethodsData come from the multisite Pathways to Desistance project, a longitudinal study of serious juvenile offenders in the United States who were interviewed across 11 time points over 7 years from 2000 to 2010. Age‐based trajectory analyses modeled self‐reported atypical lying features from ages 14 to 26 for male participants (N = 1170; 42.1% Black, 34.0% Hispanic, 19.2% White, 4.6% Other), and examined how subscales from the Youth Psychopathy Inventory predicted lying trajectory classes and whether those classes differed in adulthood offending and substance use.ResultsAround 5% of the sample maintained elevated atypical lying features in adolescence and into adulthood. These individuals were more manipulative, remorseless, impulsive, and irresponsible in adolescence, and were more likely to offend and use substances in adulthood.ConclusionsFindings highlight how atypical lying features during the normative developmental desistance period of lying may be elevated for prolific liars and how traits can be used to identify at‐risk individuals. This information will help to inform intervention and prevention programs targeting externalizing behaviors.