Edward Stern, J.D., stated that at times, a psychologist will be called upon to be an “expert” witness in a case that may proceed to a court trial. Today in the United States, although the figures vary greatly from jurisdiction to jurisdiction, about 10 percent of cases started in a court actually proceed to a completed trial.

Who exactly are forensic psychologists?

According to Lepage Associates, Solution-Based Psychological and Psychiatric Services, this is one of the most common questions they receive when clients or attorneys are looking for the best kind of support for their legal cases. Though the title “forensic psychologist” often conjures up misleading images from crime shows, psychologists can genuinely play a pivotal role in multiple parts of the legal process.

As expert witnesses, psychologists can provide both factual testimony and clinical opinions in family, civil, and criminal courts. Psychologists typically provide their educational background, curriculum vitae (CV), and other relevant information about their clinical and forensic experience. If asked to testify, a psychologist must be qualified as an expert in court with the judge’s approval. The psychologist may testify as a general expert on a topic, as an expert specific to the parties and case if he or she has treated or evaluated a party. Therapists also sometimes testify as fact witness versus expert witnesses.

An attorney can retain a psychologist to speak about their research – or the general state of science – on a particular topic. In these instances, the psychologist is acting as a general expert (on the topic), versus an expert who has met with any of the parties and evaluated them specifically. For example, an expert on childhood trauma could provide information on trauma symptoms to a judge or jury. A psychologist can also speak on a topic of concern (e.g., parental alienation) by defining it, describing it for the court, and describing how it manifests or is relevant to the legal case.

As an expert witness and evaluator, a forensic psychologist can be retained for specific legal matters and fairly and objectively answer such questions. Psychologists can provide both written evaluations and oral expert testimony. Many forensic evaluations include common elements – clinical interviews, collateral interviews (e.g., treatment providers, family, friends), psychological testing, a review of records, and conclusions. Records can be wide in scope and include legal documents, mental health records, depositions, emails/texts between parties, and copies of social media posts. The content and test selection, however, differ significantly based on the court and referral questions. Evaluators testify as expert witnesses since they form a clinical opinion on the case.

Another avenue where psychologists can give helpful information is as a treating psychologist, i.e., a therapist. If a plaintiff, defendant, or other court-involved party has a psychologist as an individual therapist, that therapist can comment on the course of treatment with their client as a fact witness. As a fact witness, however, a treating psychologist could not answer questions such as, “Do you believe he or she was insane at the time of the offense?” For a therapist to be asked about their clinical opinion, they should be sworn in as an expert.

Family Court

Psychologists can assist attorneys and judges in divorce, custody, and guardianship or legal capacity cases. Psychologists can conduct full-scale custody evaluations to help determine the ideal custody arrangement for parents and children, parental capacity evaluations that assess an adult’s ability to safely parent their children, or general psychological evaluations for children and adults to provide clinical information and treatment recommendations to the court. Testing can include but is not limited to personality tests and assessments of parental stress, substance use, or anger. By conducting thorough evaluations, forensic psychologists can weigh in with their clinical opinions and diagnostic impressions. Family courts can also determine a person’s competency to make medical, financial, or legal decisions, and intelligence, memory, and cognitive testing can give insight into specific capacities for certain types of decision-making.

Civil Court

The civil court sees a wide breadth of cases. One common area for psychologists to give expert opinions is regarding emotional distress and mental health problems incurred by a plaintiff. Personality tests and trauma inventories can help elucidate the extent of such distress. Immigration evaluations by psychologists are also commonly requested in civil court.

Criminal Court

In criminal court, psychologists are often court-appointed to conduct competency evaluations to help determine if a defendant can “understand and assist” in the trial process. Tests of personality and psychological functioning, specific competency assessments, and tests of malingering with validity scales are common for competency evaluations. Psychologists can also perform general psychological evaluations and risk assessments to gauge an individual’s risk of future violence or sexual offense. The results of these evaluations allow psychologists to give specific recommendations for treatment and risk reduction to benefit both community safety and the defendant. Contrary to media portrayals, the “insanity defense” is only raised in one percent of cases. However, forensic psychologists are qualified to evaluate someone’s mental state at the time of the offense.


This article explained a few of the ways psychologists can be integral participants in legal cases, and how they can. Testify, which is most often as an expert witness versus as a fact witness. The examples included are not exhaustive. The scope of psychologists’ involvement in the legal system continues to grow. Legal professionals have increasingly turned to psychologists to give insight into important and sometimes ambiguous questions about individuals, families, and the capacity for change. Forensic psychologists possess the training and expertise to help courts make informed decisions that affect millions of people. If you are a legal professional or a client who is court-involved, consider consulting with a forensic psychologist to assist in objective and fair representation.

This article is provided by Dr. Ralph Kueche (Child Psychologist). Dr. Kuechle is a Child and Adolescent Clinical Psychologist who specializes in treating children and their families who may be struggling with mood and behavioral issues. Learn more about Dr. Kuechle.