Assessing Legal Competency through Forensic Psychology

Every person facing criminal charges has a fundamental right: the right to understand what is happening in their case and to participate meaningfully in their own defense. But what happens when a defendant’s mental health, cognitive ability, or psychological state makes that participation impossible? This is where legal competency comes in – a foundational concept in forensic psychology that directly shapes whether a trial can proceed. Forensic psychologists play a central role in evaluating competency, ensuring that justice is not only served but served fairly.

What is legal competency? 🔗

Legal competency, often called competency to stand trial (CST), refers to a defendant’s present mental ability to understand the charges against them, comprehend the court proceedings, and work with their defense attorney. It is not about whether the person was mentally well at the time of the crime – that falls under the separate concept of the insanity defense. Competency is strictly about a defendant’s current mental state during the legal process.

In simple terms, a competent defendant must be able to do three things: understand the nature and seriousness of the charges, grasp how a courtroom works (the roles of the judge, jury, prosecutor, and defense attorney), and communicate effectively with their own lawyer to assist in building a defense. If any of these abilities are significantly impaired due to a mental disorder, intellectual disability, or neurological condition, the question of incompetency arises.

The legal standard: Dusky v. United States 🔗

The modern legal framework for competency assessments traces back to the 1960 U.S. Supreme Court case Dusky v. United States. Milton Dusky, a man diagnosed with schizophrenia, was convicted and sentenced to 45 years. The Supreme Court reversed the conviction, ruling that merely being oriented to time and place was not sufficient to establish competency. The Court established a two-pronged test: a defendant must have a sufficient present ability to consult with their lawyer with a reasonable degree of rational understanding, and they must have both a rational and factual understanding of the proceedings.

This Dusky standard remains the benchmark used across virtually all U.S. jurisdictions today. It shifted the focus from a superficial check of awareness to a deeper evaluation of whether a defendant can genuinely participate in the adversarial legal process. Importantly, the Dusky standard was later reaffirmed in Godinez v. Moran (1993), where the Supreme Court held that the same competency threshold applies to pleading guilty and waiving the right to counsel.

Who raises the question of competency? 🔗

A competency evaluation can be requested at any stage of the criminal proceedings – from arrest through sentencing. The request can come from the defense attorney, the prosecutor, or the judge. Defense attorneys raise concerns about their client’s competency in roughly 8% to 15% of felony cases. Once the concern is formally raised, the court typically orders a forensic evaluation to determine whether the defendant meets the legal threshold for competency.

It is worth noting that having a mental illness alone does not make someone incompetent. A person may have a psychiatric diagnosis – depression, anxiety, or even schizophrenia – and still be fully capable of understanding the proceedings and assisting their lawyer. The key question is whether the symptoms of a condition interfere with the specific abilities required for competent participation in legal proceedings.

How forensic psychologists assess competency 🔗

Competency evaluations are the most commonly requested type of forensic mental health assessment. The U.S. Department of Justice has noted that between 2% and 8% of all felony defendants are referred for such evaluations. These assessments are thorough, multi-step processes conducted by forensic psychologists or psychiatrists, and they go far beyond a simple conversation with the defendant.

Clinical interviews 🔗

The cornerstone of any competency evaluation is the clinical interview. During this structured conversation, the forensic psychologist assesses the defendant’s understanding of the charges and potential consequences, their knowledge of how a courtroom functions, their ability to describe the facts of their case, and their capacity to communicate with and trust their attorney. The evaluator also observes the defendant’s behavior, demeanor, and responsiveness throughout the session – subtle cues that reveal a great deal about mental functioning.

Standardized assessment instruments 🔗

In addition to the clinical interview, forensic psychologists often use standardized psychological tools specifically designed for competency evaluations. According to Vienna Psychological Group, instruments for evaluating competency were first introduced in the 1960s and have evolved considerably since. Some of the most widely used tools include the MacArthur Competence Assessment Tool – Criminal Adjudication (MacCAT-CA), the Evaluation of Competency to Stand Trial – Revised (ECST-R), the Competency Assessment Instrument (CAI), and the Georgia Court Competency Test (GCCT). These instruments measure a defendant’s factual and rational understanding of legal proceedings as well as their ability to consult with counsel.

Psychologists may also administer broader cognitive tests like the Wechsler Adult Intelligence Scale (WAIS-IV) to evaluate memory, processing speed, verbal fluency, and overall intellectual functioning – all of which bear directly on the abilities required for competency.

Collateral information and record review 🔗

A competency evaluation does not rely solely on the defendant’s self-report. Forensic psychologists review medical, psychiatric, and criminal records and may also conduct collateral interviews with family members, employers, or treatment providers. Comparing subjective data from the defendant with objective data from records and third-party reports helps confirm or challenge the picture that emerges from the clinical interview.

The forensic report 🔗

After gathering all data, the forensic psychologist produces a comprehensive written report for the court. This report summarizes the evaluation methods used, the defendant’s background, their current mental functioning, and the psychologist’s professional opinion on whether the defendant meets the legal standard for competency. The report may also include treatment recommendations if the defendant is found incompetent. While the psychologist’s opinion carries significant weight, the final determination of competency is always made by the judge.

What happens when a defendant is found incompetent 🔗

When a court determines that a defendant is not competent to stand trial, the criminal proceedings are paused. The defendant is then typically referred for competency restoration – a process involving psychiatric treatment and legal education designed to bring the individual to a point where they can meaningfully participate in their case.

Competency restoration usually involves a combination of medication management (particularly for psychotic disorders like schizophrenia), psychoeducation about court procedures, and individual coaching sessions. This can take place in an inpatient forensic hospital, a jail-based program, or in some cases, an outpatient community setting. Research shows that approximately 9 out of 10 defendants who undergo restoration are eventually found competent and proceed to disposition of their charges.

However, restoration is not always possible. In cases involving severe intellectual disability, advanced dementia, or treatment-resistant psychosis, a defendant may be deemed non-restorable. When this happens, charges may be dropped and the individual may be subject to civil commitment proceedings if they pose a risk to themselves or others. The U.S. Supreme Court addressed this in Jackson v. Indiana (1972), ruling that a defendant cannot be held indefinitely solely on the basis of incompetency.

Competency beyond the defendant 🔗

While competency to stand trial is the most frequently evaluated form of legal competency, forensic psychologists also assess competency in other contexts within the court system.

Witness competency 🔗

Courts may question whether a witness – particularly a child, an elderly individual, or someone with a cognitive impairment – is competent to provide reliable testimony. Forensic psychologists can evaluate a witness’s capacity to perceive events accurately, recall them, distinguish truth from falsehood, and understand the obligation of an oath. This is especially important in cases where the prosecution’s case hinges on the testimony of a vulnerable witness.

Competency of professionals 🔗

Forensic psychologists are sometimes called upon to assess the professional competency of individuals in positions of authority – for instance, whether a medical professional exercised adequate clinical judgment, or whether a psychologist’s evaluation in a prior case met accepted forensic standards. These assessments help courts determine liability, malpractice, or fitness for duty.

Competency in civil matters 🔗

Outside of criminal law, forensic psychologists evaluate competency in civil contexts such as testamentary capacity (the ability to make a valid will), contractual capacity (the ability to enter into a legal agreement), and the need for conservatorship or guardianship. These evaluations use similar methods – clinical interviews, cognitive testing, and record reviews – but are measured against different legal standards.

The role of the forensic psychologist as expert witness 🔗

When competency is disputed, forensic psychologists frequently serve as expert witnesses in court. Unlike lay witnesses who describe what they observed, expert witnesses provide professional opinions informed by scientific knowledge and clinical evaluation. Forensic psychologists testifying on competency must communicate complex psychological findings in a way that judges and attorneys can understand. They may be cross-examined by opposing counsel and must defend their methods, conclusions, and the validity of the instruments they used.

This role demands not only deep clinical expertise but also strong communication skills and a commitment to impartiality. The forensic psychologist is not an advocate for either side – they are an independent evaluator whose job is to help the court make an informed decision.

Why competency matters for justice 🔗

Competency evaluations are not a technicality or a legal loophole. They exist to protect a fundamental principle: no person should be tried, convicted, or sentenced if they cannot understand or participate in the process. Trying an incompetent defendant undermines the integrity of the legal system and violates the constitutional right to due process.

At the same time, competency evaluations protect society. They ensure that defendants who need mental health treatment receive it, and they provide a pathway – through restoration – to eventually hold individuals accountable when appropriate. The forensic psychologist sits at the intersection of these goals, applying clinical science to one of the law’s most important questions.

What do you think? Should the legal system invest more in outpatient competency restoration programs as an alternative to lengthy inpatient hospitalizations? And how do you think the challenge of assessing competency in juvenile defendants – who may lack maturity rather than mental capacity – should be addressed?

References

1. https://www.forensicpsychologyedu.org/insanity-and-competency-to-stand-trial/
2. https://en.wikipedia.org/wiki/Dusky_v._United_States
3. https://definitions.uslegal.com/d/dusky-standard/
4. https://www.psychiatrictimes.com/view/assessing-competency-to-stand-trial
5. https://www.justice.gov/sites/default/files/eoir/legacy/2014/08/15/Defining_and_Assessing_Competency_to_Stand_Trial.pdf
6. https://fpamed.com/determining-competence-to-stand-trial-a-brief-breakdown-by-a-forensic-psychiatric-expert/
7. https://www.viennapsychologicalgroup.com/how-do-forensic-psychologists-determine-criminal-competency/
8. https://criminal-justice.iresearchnet.com/forensic-psychology/competency-to-stand-trial/
9. https://jaapl.org/content/early/2019/02/08/JAAPL.003819-19
10. https://www.expertinstitute.com/resources/insights/the-forensic-psychology-expert-witness-guide/
11. https://www.expertinstitute.com/resources/insights/psychology-expert-witnesses-the-ultimate-guide/