Forensic Expert Witness

Data and Metrics are Filtered for Bias

Just as a physician administers tests, such as an MRI, EKG or CT scan to diagnose a patients’ illness, a psychologist uses psychological tests to assist in diagnosing mental illness and psychological problems. The most respected psychological tests used are standardized and allow the psychologist to compare the patient with a normal population of adults or children of the same age. The results of such testing can be used as demonstrative evidence when the psychologist testifies. Test data becomes a way for the psychologist to present hard data to the judge and jury. Psychological testing adds significant credibility when the psychologist testifies in court. Computerized test interpretations further provide access to a large, normative base, which assists in eliminating examiner bias.

There are a number of psychological tests proven to be valid and reliable in assessing symptoms of mental illness, emotional distress, cognitive and intellectual impairment, and personality traits. There are also test instruments that can assess malingering and dissimulation, which frequently occur in the context of legal issues.

Objective Evaluation Can Help Support Your Argument

A psychologist testifying as an expert witness can help judges and juries better understand psychological problems that impact forensic decisions. For example, in civil cases, questions of emotional damages related to injury often arise. A psychologist who administers psychological testing can diagnose the presence of, or lack of, alleged emotional injuries related to the incident in question. Rather than making subjective statements, psychologists rely on psychological testing to confirm a diagnosis of emotional injury.

What’s the Difference?

A forensic psychologist holds a doctoral degree in a field of psychology. The forensic psychologist should have significant training in the area of psychopathology, as well as clinical training. In addition, the forensic psychologist also has advanced graduate or post-graduate training in forensic psychology. Advanced training in forensic psychology provides the psychologist with an understanding of the legal issues involved in the chosen areas of practice in forensic psychology. This training also focuses on the use of statistically sound psychological testing that enhances court credibility and provides an objective avenue for diagnosing the client. Standardized psychological testing provides a scientific basis for the psychologist’s opinion.

In contrast, a forensic psychiatrist is trained as a medical doctor with a residency in psychiatry. The residency exposes the psychiatrist to information about the use of drugs to treat mental illness, and provides the psychiatrist with education about treating various clinical populations. Forensic psychiatrists are not trained in standardized testing to provide testing substantiation for their testimony.

Thorough Assessments and Reports

When hired as an expert, Dr. McNaught reviews medical and mental health treatment records, academic records, previous psychological examinations, employment records, and other legal documents. She then proceeds with a clinical interview to obtain a social history. Well-validated, reliable psychological testing, as well as situation-specific inventories are then administered. Contact with collateral sources is conducted, as needed.

Following the evaluation, Dr. McNaught provides an oral or written report, as requested. Her reports are comprehensive and based on solid clinical assessment, as well as an objective review of the pertinent records. The goal of these evaluations is to compare psychological testing and interview data with medical, counseling, and legal records to assess credibility and psychological functioning. Such evaluations further assess pre-existing, co-existing, and post-injury events on the client’s present psychological functioning.

Typically, the referring attorney contacts Dr. McNaught regarding forensic evaluations and forensic testimony. She will obtain a brief background from the attorney regarding the referral. The attorney will be provided with a retainer agreement – to be signed by the attorney and/or client. Dr. McNaught will then request that the attorney send a letter outlining the questions to be addressed in the evaluation or court testimony. Attorneys also are asked to provide Dr. McNaught with the pertinent legal, medical and mental health documents for review prior to the client’s appointment or report summarizing her opinions.

Critiquing the work of others typically involves comparing the evaluative procedures used by the other professional to the current standard of care for the evaluation in question. Such critiques also address the psychological testing relied upon, as well as the accuracy of the conclusions based on the case material.