Most clinicians who serve as expert witnesses regard testifying in court as a necessary, sometimes unpleasant, but frequently challenging and rewarding part of their jobs. However, other clinicians whose work is not primarily with the legal system, may become intimidated if they are subpoenaed to testify at deposition or trial.

In either case, your job as an expert witness in your field of study and practice is to ensure that the facts you present tell the complete story and that your delivery of these facts makes your testimony clear, credible, and convincing. This article provides some practical recommendations for testifying in court based on a survey of the literature, the insights of some of my professional colleagues, and my own experience as an expert witness in forensic psychology (Barton, 1990; Miller, 1996, 1997, 1999a, 1999b, 2006a, 2006b, in press; Mogil, 1989; Posey & Wrightsman, 2005; Simon, 1995; Taylor, 1997; Vinson & Davis, 1993).


A fact witness is someone who has personal knowledge of events pertaining to the case and can only testify as to things he or she has personally observed ("Fred told me he was mad at his boss;" "I saw Fred slip on the grease spot and land on his back"). They may not offer opinions ("Based on Fred's behavioral profile and clinical history, he is likely to magnify symptoms and seek excessive attention and compensation for minor injuries"), which are the province of the expert witness, who, in a civil case is either retained by the plaintiff or defense or, more rarely, appointed by the court to make statements about aspects of the case that he or she has personally not observed but in which he or she has specialized training.

Experts are there precisely to offer opinions that may assist the judge or jury in understanding technical knowledge that would otherwise be beyond their expertise. This is typically the role of credentialed specialists in medicine, psychology, economics, and other fields. Although experts are typically allowed more leeway in testimony than fact witnesses, the content of their testimony may also bo carefully vetted by the court for admissibility.

Doctors and other clinical practitioners may find that their testimony sometimes straddles the domains of fact and expert witness. For example, you may be queried about what you did and what the subject did, like a fact witness, and then asked to state an opinion like an expert witness. Or you may state such an opinion, which the opposing attorney may challenge, and the judge must then decide whether or not to allow it to be admitted into the record.

  • Attorney: Dr. Sullivan, can you tell us how you arrived at your conclusion that the plaintiff sustained a concussion?
  • Expert: I reviewed the medical records, including the ER report, his family doctor's examination, and the results of the neuropsychological evaluation performed by Dr. Lopez. I also conducted a mental status assessment as part of the neurologic portion of my exam. While my own mental status exam of the patient was essentially within normal limits, he showed impairment on several tests in the neuropsych eval.
  • A: Dr. Sullivan, you're not a neuropsychologist, are you?
  • E: No, I'm a physical medicine and rehabilitation physician.
  • A: So you didn't perform the neuropsychological assessment yourself, did you?
  • E: No, it was in the record.
  • A: So when you testified earlier that "a score of 235 on Trails B suggests organic cognitive impairment," this wasn't a test that you conducted yourself or that you interpreted yourself?
  • E: No, just as other doctors rely on my records to make their assessments, I utilize their information to arrive at my diagnostic conclusions. Nobody's an expert in everything; that's why different specialists collaborate in comprehensively evaluating a patient. That's the way we do things in good clinical care.


While we're on the subject of records, experts should understand the importance of proper record keeping and strive to develop a well-organized, standardized, and readable style for writing reports - not just because these may some day be read by probing, critical eyes, but because writing out your thoughts in words is an excellent way to clarify, organize, and remember the points you want to get across, should the case ever come to trial. If helpful, draw diagrams to facilitate your description and to jog your memory. Also, don't be afraid to supplement standard forms and checklists with your own words and illustrations if this will help explain a potentially confusing procedure or diagnostic conclusion.

Review your case. And review it again. In fact, there's no such thing as too much preparation. The more thoroughly you know your facts and theories about the case, the easier it will be to answer questions thrown at you from "left field" because you won't be relying on rote memorization of individual answers to different questions; your knowledge and recollection will be an organic, holistic, automatic process that's hard to trip up by clever cross-examination. You'll probably have one or more meetings with your retaining attorney to go over your testimony. Ideally, the purpose of this consultation is not for the attorney to spoon-feed your words to you, but for both of you to clarify the substance of your testimony, to agree on a terminology that will best express what you have to say, and to get a sense of what you will be asked by both sides

Rehearse. Most of this will be mental rehearsal, going over the facts of the case and your testimony in your head. You might also rehearse out loud, while driving in your car or in front of a mirror at home. If trial testimony is unfamiliar to you, visit a courtroom and observe other trials in progress. But even for the most seasoned witness, there is no substitute for adequate preparation, and many a veteran expert has let his or her overconfidence lead to loose ends which are then used by a clever opposing counsel to hang them.


Certainly, most important aspects of courtroom demeanor cannot be programmed; every witness brings his or her own unique style to the stand. Nevertheless, there are a few principles of effective testimony that all witnesses can productively apply.

Your general attitude should be one of confidence, but not cockiness. To the average juror, a doctor or other professional conveys an air of authority and respect; use this to your advantage. Maintain composure and dignity at all times. Remember, no matter how nasty the cross-examination, you are not the one on trial here. It's not you who will ultimately decide the case for plaintiff or defendant; your job is to present the facts and evidence, and then let the legal process do its job. As with all aspects of your practice, always remember that you are a professional and behave accordingly.

Body language is important. Like your mother said, sit up straight and don't slouch. If there's a microphone in front of you, sit close enough so that you don't have to lean over every time you speak. If you're in a swivel chair, try to avoid twisting and spinning; make a conscious effort to plant your feet on the floor while speaking. Keep your presentation materials neatly organized in front of you, so you can find documents and exhibits when you need them.

While testifying, look at the attorney while he or she is questioning you, then switch your eye contact to the jury while answering the question; it's them you have to establish a connection with, and jurors tend to find witnesses more credible when they "look straight at us." Be neither overly aloof nor overly intense. Open, friendly, and dignified are the attitudinal words to remember. Speak as clearly, slowly, and concisely as possible to be understood. Keep sentences short and to the point. Keep your voice tone steady and use a normal conversational tone. Don't mumble, shout, or waffle, but neither should you speak in a robotic monotone. Your general attitude toward the jury should convey a sense of collegial respect: you are there to present the facts as you know them to a group of mature adults who, you are confident, will make the right decision.

Listen carefully to each question before you respond. If you don't fully understand the question, ask the attorney to repeat or rephrase it. Don't be baited into giving a quick answer; if you need a couple of seconds to compose your thoughts, take them. Speak as clearly and concisely as possible. Answer the question completely, but don't over-elaborate or ramble. If you don't know the answer to the question, state plainly, "I don't know." Don't try to bluff your way out of a tricky question. The opposing attorney will manage to seize on the one piece of evidence you didn't present or the one inconsistency in your testimony and try to use it to hang you. Don't become defensive. Above all, be honest. If anyone in the courtroom detects even a whiff of deliberate BS, especially from a doctor or other professional they're supposed to be able to trust, it will stink up the remainder of your entire testimony.

Attorneys will often phrase questions in a way that constrains your answers in the direction they want you to go. If you feel you cannot honestly answer the question by a simple yes-or-no answer, say so: "Sir, if I limit my answer to yes or no, I will not be able to give factual testimony. Is that what you wish me to do?" Sometimes, the attorney will voluntarily reword the question. If he or she presses for a yes-or-no answer, at that point either your attorney will probably pop up to voice an objection or the judge will usually intervene. The latter may instruct the cross-examining attorney to allow you more leeway in responding, or to rephrase his or her question, or the judge may simply order you to answer the question as it has been asked, in which case that's what you do - with a resigned look on your face.

Another attorney ploy is to phrase questions in such a way as to force you to respond in an ambiguous manner, often prefacing your answer with such wishy-washy phrases, as "I believe," "I estimate," "To the best of my knowledge/recollection," "As far as I know," "What I was able to ascertain," "I'm pretty sure that," etc. If the facts warrant it, be as definite about your answers as possible; if they don't, honestly state that this particular piece of your testimony may not be a clear perception or recollection, but be firm about what you are sure about.

In general, try not to answer beyond the question. For example, if the attorney asks you to phrase your answers in precise measurements that are not relevant to the data or that you cannot accurately recall, don't speculate, unless you are specifically asked to do so.

  • Attorney: Dr. Sullivan, you testified that the plaintiff's range of motion on her injured joint was in the moderately impaired range. Doctor, for that joint, how many degrees of angle is considered the dividing line for "moderately impaired"?
  • Expert: Normal range of motion for that joint should be between 120 and 160 degrees. The patient's obtained maximum range was 90. That's considered within the moderately impaired range.
  • A: So 90 degrees is the cut-off for "moderate impairment"?
  • E: It's not a strict cut-off, like 32 degrees Fahrenheit equals freezing. Orthopedically, 90 degrees maximum range of motion in that joint - in conjunction with clinical observation of inflammation, subjective reports of pain, and X-ray records of an incompletely healed fracture with scar tissue - add up to my clinical judgment that this patient's impairment is in the moderate range.

A related ploy is for the attorney to ask you to estimate something reasonable, like the amount of time that has passed (which most people can roughly gauge in terms of minutes or hours), and then switch to other topics, while maneuvering you to preserve the estimative mindset. Now, everything you say has become an "estimate" or something recalled "to the best of my recollection." Later, in his or her summation, opposing counsel will state something like this:

"And Dr. Sullivan really hasn't described anything solid has he? Everything is an estimate, a guess, an inference. Ladies and gentlemen of the jury, is a loose collection of "maybe's" and "I-guess-so's" sufficient evidence to warrant the type of exorbitant compensation this plaintiff is asking?"

Again, this doesn't mean you should inject false surety into naturally iffy information, but try to emphasize that the ambiguity lies with the subject matter, not with your own perceptions and interpretations.

  • Attorney: Dr. Lopez, you stated in your report that, quote: "the inconsistencies in test scores and well as in the subject's behavior raise the strong possibility of malingering or other response manipulation;" unquote. You've already described the test results to us, so I'd like to focus on the behavioral part. Can you tell this court which specific behaviors indicate malingering and which do not?
  • Expert: The patient claimed that he had suffered persistent severe memory loss following the car accident, yet during the ensuing year, he received a promotion to senior sales manager at his job where he continued to work a full schedule.
  • A: And which specific features of his job description require intact memory and which do not?
  • E: I haven't conducted or reviewed a formal job analysis.
  • A: So you can only guess that his work involves intact memory?
  • E: Based on the scientific literature on cognitive neuropsychology, it would be highly unlikely that the plaintiff could manage a busy, fast-paced sales office with the degree of memory problems he subjectively reports and the extremely low scores he produced on most of the neuropsychological tests.
  • A: Unlikely, but possible?
  • E: Well, it would be like a person claiming to be paraplegic observed to be working as a police officer or mail carrier

Again, if you don't know the answer to a question, just say you don't know. Jurors will respect and appreciate honest ignorance of a few details far more than a apparent attempt to make everything "fit" with your testimony.


Remember, an important part of trial testimony is the impression you make on the jury by your demeanor, language, and grace under pressure, so avoid either being cowed into submission or baited into an angry overreaction. Yes, easier said than done. But that's one more reason to go over your testimony before the trial: to anticipate challenges and become comfortable with the substance of your case, so you minimize the chance of being coldcocked by an unanticipated question or challenge.

Finally, remember that most citizens, including most jurors, want to believe that the people they place their trust in - doctors, police officers, and others - have their best welfare in mind. This means that they will mentally bend over backward to give you the benefit of the doubt if you can give them a credible reason to do so. It also means that if you betray them through dishonesty or flagrant disrespect, they may come down on you especially hard for violating that trust. Prepare carefully for your case, be clear and honest in your testimony, maintain dignity and decorum, and in most cases you'll walk out of court with a wry smile.


  • Barton, W.A. (1990).Recovering for psychological injuries (2nd ed.). Washington DC: ATLA Press.
  • Miller, L. (1996). Making the best use of your neuropsychology expert: What every neurolawyer should know. Neurolaw Letter, 6, 93-99.
  • Miller, L. (1997). The neuropsychology expert witness: An attorney's guide to productive case collaboration. Journal of Cognitive Rehabilitation, 15(5), 12-17.
  • Miller, L. (1999a). Psychological syndromes in personal injury litigation. In. E. Pierson (Ed.), 1999 Wiley expert witness update: New developments in personal injury litigation (pp. 263-308). Rockville: Aspen.
  • Miller, L. (1999b). "Mental stress claims" and personal injury: Clinical, neuropsychological, and forensic issues. Neurolaw Letter, 8, 39-45.
  • Miller, L. (2006a). On the spot: Testifying in court for law enforcement officers. FBI Law Enforcement Bulletin, October, pp. 1-6.
  • Miller, L. (2006b). Practical police psychology: Stress management and crisis intervention for law enforcement. Springfield, IL: Charles C Thomas.
  • Miller, L. (in press). From difficult to disturbed: Understanding and managing dysfunctional employees. New York: Amacom.
  • Mogil, M. (1989). Maximizing your courtroom testimony. FBI Law Enforcement Bulletin, May, pp. 7-9.
  • Posey, A.J. & Wrightsman, L.S. (2005). Trial consulting. New York: Oxford University Press.
  • Simon, R.I. (1995). Toward the development of guidelines in the forensic psychiatry examination of posttraumatic stress disorder claimants. In R.I. Simon (Ed.), Posttraumatic stress disorder in litigation: Guidelines for forensic assessment (pp. 31-84). Washington DC: American Psychiatric Press.
  • Taylor, J.S. (1997).Neurolaw: Brain and spinal cord. Washington DC: ATLA Press.
  • Vinson, D.E. & Davis, D.S. (1993). Jury persuasion: Psychological strategies and trial techniques. Little Falls, NJ: Glasser Legalworks.

Laurence Miller, PhD is a clinical and forensic psychologist and law enforcement educator and trainer based in Boca Raton, Florida. Dr. Miller is the police psychologist for the West Palm Beach Police Department, a forensic psychological examiner for the Palm Beach County Court, and a consulting psychologist with several regional and national law enforcement agencies. Dr. Miller is an instructor at the Criminal Justice Institute of Palm Beach County and at Florida Atlantic University, and conducts continuing education and training seminars around the country. He is the author of numerous professional and popular print and online publications pertaining to the brain, behavior, health, law enforcement, criminal justice, and organizational psychology. His latest books are Practical Police Psychology: Stress Management and Crisis Intervention for Law Enforcement (Charles C Thomas) and From Difficult to Disturbed: Understanding and Managing Dysfunctional Employees (Amacom). Dr. Miller can be contacted at (561) 392-8881 or online at

Disclaimer: This article is for educational purposes only and is not intended to provide specific clinical or legal advice.

Article © 2007, Laurence Miller, PhD. All rights reserved. This article may not be reproduced in whole or in part without express written permission of the author.