Social mechanisms of judicial decisions: an explanatory mixed-methods research design on juvenile sentencing. This article discusses the social mechanisms of judicial decisions. The purpose is to explain the decision-making process that culminates in the application of the confinement disposition in the juvenile justice field. The research consisted of an explanatory mixed-methods design. At first, the existing hypotheses were tested with a representative sample of adolescents who went through the courts between 1990 and 2006. Subsequently a juvenile justice courtroom was visited. The results indicate that the standard mechanism of juvenile justice involves decisions taken from police reports, creating a proportionality between the severity of the infraction and the severity of the measure applied; and that there are situations in which the definition of the situation is broken, causing operators to take lenient measures for young, white, non-drug users who study or work. doi.org/10.20336/rbs.205.