A review of the existing research on adolescent decision making in legal contexts, including competence to stand trial, highlights the limitations of the existing research and outlines a methodology to address some of the current gaps in knowledge. Goals of the current research were to investigate how juveniles compared to adults on state-of-the-art assessments of competence-related abilities that are increasingly used with adult defendants and to examine how the development of decision making capacity and judgment may differentially impact a juvenile's competence-related abilities compared to adults. For Part I of the current study, data were collected from 100 males aged 15 and younger, 100 males aged 16 and 17, and 115 males ages 19 to 35. Participants were selected for inclusion based on their gender, age, and pretrial detention status. Measures of adjudicative competence, noncontextual judgment factors, and context-specific judgment factors were administered in interview format. In Part I of this study, the data supported hypotheses that claimed scores on non-legal context and context-specific judgment factors would change across age, and they would be related to decision making process and outcomes in the legally relevant vignettes. The two juvenile samples were significantly different from adults on several noncontextual and contextual measures of judgment, although the patterns varied depending on the specific factors considered. Some expected age differences were also found when reporting the possible consequences of decisions in the two vignettes. Further, demographics, adjudicative competence, and noncontextual and context-specific judgment factors all played some role in predicting respondents' decisions in the hypothetical vignettes. The study's central conclusion, even with the limitations noted, is that age-based differences in judgment constructs relate to decision making process and outcome in legally relevant contexts. 19 tables and 61 references