Forensic Psychologists in Determining Insanity and Competency to Stand Trial

Television courtroom dramas have introduced the masses to phrases like “not guilty by reason of insanity” and “not competent to stand trial.” But what do these phrases really mean, and do they have a place in real-life courtroom settings?

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Forensic psychologists frequently address the essential components of competency and insanity, both of which are used to evaluate an individual’s fitness to stand trial. Lawyers and the courts rely on the expertise of forensic psychologists to understand these concepts and make professional determinations based upon their legal definitions.

Competency refers to a defendant’s capacity to comprehend the allegations, while insanity refers to the mental state of the defendant at the time of the crime.

What is Competency?

Competency determines whether a defendant will be able to appear at trial and understand the proceedings. More specifically, the Supreme Court found that to be competent a defendant must:

  • Have the ability to consult with an attorney with a reasonable degree of rational understanding
  • Have a rational and factual understanding of the proceeding

What is Sanity/Insanity?

Sanity determines whether a defendant is capable of being held responsible for his/her criminal actions. The definition of insanity varies from one state to the next, and some states have no insanity defense at all.

The insanity defense is based on the assumption that the defendant was not of sound mind when the crime was committed and is therefore incapable of appreciating the true nature of the crime.

Defendants who are found competent to stand trial may still be found not guilty by reason of insanity, although defendants found not competent to stand trial can never be found guilty or not guilty because a trial cannot happen in the first place.

Insanity may be defined a number of ways:

  • Legally determined: A defendant lacks criminal responsibility because of a mental disorder or defect and therefore lacks the capacity to appreciate the crime
  • Morally determined: A defendant lacks criminal responsibility as a result of a mental disorder or defect and therefore lacks the capacity to appreciate the misconduct as a violation of ethical behavior according to society
  • Subjectively determined: A defendant lacks criminal responsibility because of a mental disorder or defect due to a belief that committing the crime is morally justified, despite as an awareness that the actions were illegal or were a violation of social-moral standards


The Main Differences Between Determining Competency and Insanity

A judge determines competency; a jury determines insanity. Therefore, competency is determined before a trial commences, while insanity is determined at the end of trial with the verdict.

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An attorney can raise competency as an issue, or a judge may base a finding of competency based on observation. If there is a reasonable basis to believe that competency is an issue, the court orders an evaluation, usually by a forensic psychologist. Based on the outcome of the evaluation, the judge determines whether the defendant is competent to stand trial. The defendant; however, must plea insanity.

Competency is part of the due process clause of the Constitution and is therefore part of U.S. federal law.

State law determines insanity, and each state has different parameters under which insanity is measured. Some states have no insanity defense.

The Consequences of Competency and Insanity in the Legal Process

Judges evaluates competency based on a defendant’s mental state at the time of the legal proceeding/trial. The judge bases a decision on the result of a forensic psychologist’s evaluation. If a judge finds a defendant incompetent to stand trial based on the forensic psychologist’s evaluation, the criminal proceeding is halted and the defendant receives treatment until the time they are deemed competent.

When evaluating insanity, the jury considers the defendant’s mental state at the time the crime was committed. A forensic psychologist provides a professional opinion regarding an insanity defense. If a jury finds a defendant to be insane (either GBMI-Guilty but Mentally Ill or NGRI-Not Guilty by Reason of Insanity), the defendant is typically admitted into a psychiatric hospital.

Commitment procedures vary, depending on the state. Some states require a commitment hearing, while other states allow the commitment to automatically take place.

Practice Guidelines for Determining Insanity

One of the major issues when determining insanity is that insanity is considered a legal concept, not a psychiatric one. This means that suffering from a mental disorder does not automatically prove insanity. Therefore, it is the job of a forensic psychologist to determine if the disorder caused the defendant to lack an appreciation of the crime at the time it was committed.

In the United States, “not guilty by reason of insanity” represents just one percent of all criminal cases. Within this small percentage, the defense is able to legally prove insanity just 25 percent of the time.

Forensic psychologists must determine if a defendant was unable to appreciate or distinguish between right and wrong at the time of the crime. To do so, they typically use one of the following clinical tests:

  • Slobogin Mental Screening Evaluation
  • Rogers Criminal Responsibility Assessment Scales

The assessment process is a complex one. Forensic psychologists must evaluate information from a number of sources and conduct diagnostic interviews and tests before providing the court with the results of their evaluation and their professional opinion.

Practice Guidelines for Determining Competency to Stand Trial

The American Academy of Psychiatry and the Law estimates that competency evaluations in the U.S. number about 50,000 to 60,000 annually. Determining whether a defendant meets a jurisdiction’s criteria for competency to stand trial has become a core skill in the field of forensic psychology.

Forensic psychologists utilize a number of instruments to determine competency to stand trial, from screening tools to elaborate guides for conducting evaluations. Some of the more popular screening tools used by forensic psychologists include:

  • The Competency to Stand Trial Screening Test (CST), a 22-item, standardized test developed by the National Institute of Mental Health
  • The Competency to Stand Trial Assessment Instrument (CAI), a semi-structured, comprehensive interview that scores individuals on 13 areas of competence-related functioning
  • The Georgia Court Competency Test (GCCT), a popular screening instrument that evaluates a defendant’s factual knowledge about general criminal court procedures and factual knowledge related to the specific case
  • The Evaluation of Competency to Stand Trial-Revised (ECST-R), a recently developed assessment instrument that addresses a defendant’s factual and rational understanding of legal proceedings and the ability to consult with counsel

Based upon assessment instruments, interviews, and related tools, forensic psychologists must be able to formulate a forensic opinion. To do so, they consider three questions:

  • What symptoms do the defendant display, and what is the psychiatric diagnosis?
  • What is the relationship (if any) exists between the symptoms/diagnosis and the mental capabilities required under the jurisdictions’ standard for competence to stand trial?
  • If the defendant appears incompetent to proceed, how likely is it that restoration services would restore competence, and what is the appropriate setting for such services?

Most adults found incompetent to stand trial meet criteria for a mental disorder as defined by the American Psychiatric Association.

Certification Options for Forensic Psychologists Who Determine Insanity and Competency to Stand Trial

Beyond a doctoral degree in forensic or clinical psychology and a state license to practice clinical psychology, forensic psychologists interested in pursuing a career that involves determining insanity and competency to stand trial may receive valuable experience by completing forensic psychology internships and post-doctoral fellowships with law firms specializing in this area of forensic psychology.

Professional certification through the American Board of Professional Psychology Specialty Certification (ABPP) in forensic psychology is another way to advance in the profession.

To qualify for ABPP certification in forensic psychology, candidates must be state licensed and must meet the following competencies in forensic psychology:

  • Must have completed at least 100 hours of formal education, direct supervision, or continuing education in forensic psychology after the date the doctoral degree was earned; AND
  • Must have at last 1,000 hours of experience in forensic psychology, which was obtained by completing at least 5 years of post-doctoral experience (an LLB or JD degree may be substituted for two of the five years of experience); OR
  • Must have at least 2,000 hours of post-doctoral training in forensic psychology, meeting APA curriculum guidelines

Professional certification requires the completion of a written and oral examination and the satisfactory completion of the credential review process.

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ABPP’s requirements of at least 100 hours of post-doctoral education, direct, supervision, or continuing education is the ideal time to seek additional instruction in the areas of insanity/competency to stand trial.

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