Evaluation of Competency to Stand Trial–Revised (ECST–R) is a semistructured interview that is designed to assess criminal defendants' capacities as they relate to courtroom proceedings. In Dusky v. United States(1960), the U.S. Supreme Court established the three basic prongs required for competency to stand trial: (1) factual understanding of the proceedings, (2) rational understanding of the proceedings, and (3) rational ability to consult with counsel. The ECST–R was developed and validated for assessment of the Dusky prongs. In addition, the ECST–R includes a specific screen for feigned incompetency.