Competency to Confess

Competency to confess refers to a suspect’s ability to make a knowing, intelligent, and voluntary waiver of the Miranda warnings at the time of police questioning. Confessions that are given after a suspect waives his or her Miranda rights are sometimes challenged on the basis that the suspect was not competent to confess, meaning that the suspect was not capable of making a knowing, intelligent, and voluntary waiver of the Miranda rights and therefore could not have understood, appreciated, and willingly waived those rights. A confession that is successfully challenged cannot be used in court against the defendant. Assessment of competency is therefore performed after the confession is given. This assessment is performed by a mental health professional (often a forensic psychologist) and takes into account the defendant’s ability at the time of the interrogation to understand the warnings and make intelligent use of them and the psychological factors that could be relevant to the court in assessing the voluntariness of the waiver.

In the 1966 Miranda v. Arizona case, the U.S. Supreme Court ruled that any statement arising from the custodial interrogation of a suspect would be presumed involuntary and thus inadmissible unless the police provide the suspect with four warnings: (1) the suspect has the right to remain silent, (2) any statements made by the suspect can be used in court against him or her, (3) the suspect has the right to the presence of an attorney before and during the interrogation, and (4) an attorney will be provided free of charge if the suspect does not have the ability to pay for one. Many jurisdictions have added a fifth prong, that these rights can be invoked at any time during the interrogation process and that once they are invoked, the questioning must cease until an attorney is present. The U.S. Supreme Court in the Miranda decision opined that these rights must be waived knowingly, intelligently, and voluntarily. Case law has clarified the meaning of these three prongs.

The term competency to confess is a misnomer because it explicitly refers to one’s ability to understand and appreciate the significance of the Miranda rights at the time of police questioning. It also refers to the psychological characteristics of a defendant that have an impact on the voluntariness of the Miranda waiver. Thus, this competency differs from other competencies (e.g., competency to stand trial, competency to consent to treatment) in that the mental health professional must examine the individual’s competence at some point in the past. The court is not concerned with current or future competency with respect to Miranda warnings; rather, the court is concerned about whether the defendant was able to make a knowing and intelligent waiver at the time he or she was questioned by the police.

Also, not all three prongs needed to effectuate a valid Miranda waiver can be addressed completely by the mental health professional. Case law clearly indicates that for a waiver of rights to be deemed involuntary, there must be a showing of police misconduct. It has to be shown that the police were unduly coercive and overstepped their bounds in extracting a Miranda waiver. It is beyond the scope of a mental health expert’s expertise to determine whether and how that threshold was crossed. Yet psychological expertise can be useful to the court in determining whether a suspect possesses psychological characteristics that increase his or her susceptibility to the effects of police conduct. Such characteristics include interrogative suggestibility, compliance, intellectual functioning, anxiety, memory, and sleep deprivation. There are a number of specialized tests that can assist the clinician in evaluating the psychological factors relevant to the voluntary prong of the Miranda waiver.

It is within the realm of the mental health professional’s expertise to opine directly on the knowing and intelligent prongs of the Miranda waiver. A knowing waiver of rights is defined as the individual’s understanding or comprehension of the rights combined with the manner in which the rights were administered by law enforcement. For example, one would expect different levels of understanding in illiterate suspects if they were required to read the rights on their own versus having the rights read to them. An intelligent waiver of rights is different from a knowing waiver of rights. The former involves knowledge of the rights, decision-making capacity, and appreciation of the significance of the rights based on one’s knowledge of how the legal system works. Thus, while suspects may understand that they have a right to defense counsel, an intelligent waiver of the right to counsel cannot be made if they erroneously believe that a defense attorney would only work on behalf of innocent defendants.

Evaluation of a defendant’s competency to confess requires a comprehensive forensic evaluation. An extensive clinical history, examination of mental status, and record review are generally combined with psychological testing to assess a defendant’s cognitive and emotional functioning. The focus is directly on the psychological functioning that would have been displayed at the time of the police questioning. Given that the evaluation must be functionally based—that is, clinically relevant data should be integrated with the appropriate legal criteria (i.e., knowing, intelligent, and voluntary), the mental health professional must specifically assess behavior relevant to the legal criteria. Thomas Grisso developed four psychological tests to aid in the assessment of a juvenile’s or an adult’s ability to make a knowing and intelligent waiver of rights. Although these tests (like any other test) are subject to misuse, if used properly as part of a comprehensive competency assessment, they can provide useful data to the clinician and, ultimately, to the trier of fact.

The assessment of competency to confess must also take into consideration the complexity of the wording of the rights. In general, the Miranda warnings are written at approximately the seventh-grade level of reading comprehension. Yet the complexity of the wording of the rights varies greatly within and between jurisdictions.

Research has shown that 23% of adults do not understand at least one of the four Miranda rights. Moreover, 70% of adult nonoffenders and 43% of adult offenders erroneously believe that the right to remain silent is revokable by the judge. Juveniles aged 14 years and below do not understand their rights as well as older juveniles and adults. With juveniles and adults, intelligence is positively correlated with Miranda comprehension.


  1. Cloud, M., Shepherd, G., Barkoff, A., & Shur, J. (2002). Words without meaning: The constitution, confessions, and mentally retarded suspects. University of Chicago Law Review, 69, 495-624.
  2. Frumkin, I. B. (2007). Psychological evaluation in Miranda waiver and confession cases. In R. Denny & J. Sullivan (Eds.), Clinical neuropsychology in the criminal forensic setting. New York: Guilford Press.
  3. Grisso, T. (2003). Evaluating competencies: Forensic assessment and instruments (2nd ed.). New York: Kluwer Academic.
  4. Miranda v. Arizona, 384 U.S. 436 (1966).

See also: