Competency to stand trial (CST) is the competency evaluation to determine that defendants have the mental capacity to understand the charges and assist their attorneys. In the United States, this is seated in the Fifth Amendment to the United States Constitution, which ensures the right to be present at one's trial, to face one's accusers, and to have help from an attorney. CST, sometimes referred to as adjudicative competency, serves three purposes: "preserving the dignity of the criminal process, reducing the risk of erroneous convictions, and protecting defendants’ decision-making autonomy".