In the United States criminal justice system, a competency evaluation is an assessment of the ability of a defendant to understand and rationally participate in a court process.
[6] Dusky presented a petition of writ of certiorari to the Supreme Court requesting that his conviction be reversed on the grounds that he was not competent to stand trial at the time of the proceeding.
The court decided to grant the writ, based on a lack of recent evidence that the petitioner was competent at the time of the trial.
[8] Within the US criminal justice system, competence may be raised as an issue before trial, before a guilty plea, or in relation to whether a person convicted of a capital offense may be executed.
A defendant is deemed competent to stand trial if they are found to have a sufficient present ability to understand and participate in legal proceedings.
There are three ways in which one can be considered incompetent for execution: being deemed insane, having an intellectual disability, or have committed the crime subject to capital punishment while a minor.
While he may have understood that he was to receive capital punishment due to his murder conviction, his extreme delusions prevented him from rationally understanding why he was to be executed.
[2][13] Providing treatment to an individual to enable that person to become competent to be executed places mental health professionals in an ethical dilemma.
[14] The National Medical Association takes the position that ethically it is a physician's duty to provide treatment, regardless of the patient's legal situation.
[15] The Supreme Court of the United States in the Atkins v. Virginia (2002) case used the Eighth Amendment’s cruel and unusual punishment clause to determine that those with intellectual disabilities are not competent to be executed due to diminished culpability.
The Supreme Court of the United States in Roper v. Simmons (2005) decided that it was unconstitutional to execute individuals for crimes committed under the age of majority using the same reasoning in Atkins v. Virginia (2002).
Each evaluator must decide what is meant by "sufficient present ability" and "has a rational as well as a factual understanding" as set forth in the Dusky decision.
Unlike a presumption of innocence, where the defendant must be proven guilty beyond a reasonable doubt, CST is determined only by a preponderance of the evidence.
In United States v. Binion malingering or feigning illness during a competency evaluation was held to be obstruction of justice and led to an increased sentence.
While the MMPI-2 is generally quite good at detecting psychological distress, it has been criticized for not adequately focusing on the core issues of CST, an understanding of the legal system.
[7] In 1989, Kenneth Curtis of Stratford, Connecticut was initially found mentally incompetent to stand trial following the murder of his estranged girlfriend.