Current criminology and corrections research is limited in its ability to fully conceptualize and analyze inequities in the legal systems' response to young people, particularly those with multiple marginalized identities. This article presents a novel methodological framework-the Critical Case File (CCF) approach-to advance methodological innovations in criminal and juvenile legal system research. Specifically, the CCF approach leverages the rich multisystem information available within case file data and analyzes it through a critical lens to examine (a) the structural factors (e.g., economic and housing precarity) undergirding legal system contact and (b) how the legal system responds to these structural factors to perpetuate the well-documented disparities that exist across the legal continuum. In this article, we present the CCF approach, which systematizes best practices for capturing the breadth of information available within case files. We first propose a six-step methodological process to describe how information from legal system-impacted people's case files can be extracted, analyzed, and disseminated with an equity-oriented lens. We then exemplify how the CCF approach differentiates from other methods typically used in social science and criminology research. Practice and policy implications are presented to demonstrate the ways that the CCF approach can leverage case file data to generate novel, meaningful, and data-driven solutions that illuminate structural factors that may drive and exacerbate legal system contact and delineate the potential of research-practice-policy partnerships to reduce structural disparities.