As an expert witness, you must be prepared to testify.
This is far more involved than just reviewing your notes and spouting off a few facts.
Your skills were employed as a trier of fact and the OC (opposing counsel) will look for any opportunity to discredit your findings or diminish its weight with the jury. It is critical that you understand your role in the story being told to the jury.
Talk with your retaining counsel well before trial so you understand where you fit into that story. Let the attorney explain the trial process and help develop an answering strategy. They will familiarize you with the questions to expect during both the direct and cross examination, including attacks on professional and personal credibility.
If the trial preparation is being recorded, review that video to better understand your responses and body language. Be sure the attorney is aware of any facts that you know, but have not already covered. Now is also the time to discuss any weaknesses in your facts, background or training.
If the use of charts or diagrams will help present your facts, discuss
these with the attorney. Also, ask the Attorney if they are familiar with the strategies and tactics of the OC. For example, that Attorney may have
a tendency to challenge witness qualifications more than their conclusions.
During trial, listen carefully to each question and only answer what is being asked, and nothing more. Trust the attorney and let them ask follow-up questions if they feel more details are required. Pause briefly to allow the attorney time to object, and then await the
judge's ruling or the Attorney's rephrasing before providing your answer. This will prevent
you from stating potentially damaging or unnecessary information.
While it is okay to work additional facts and critical facts into your
response, don't try to remember key buzz words or phrases. Sounding scripted will harm your perceived credibility. Just stick with what you know to be true and do not concern yourself with
any thematic concepts or legal theories. If OC's question is steering
your facts to an incorrect conclusion, state the correct facts in your
complicated or excessively technical answers, unless that is the only
way to convey the facts. Likewise, avoid talking down or over
simplifying your answer. You want to engage and educate the jury, not
bore or frustrate them. This can be especially challenging for experts
with large egos and a love of their own voice. Large egos can also
encourage experts to speak beyond their qualifications, and thus
jeopardize their overall credibility.
Only use absolutes like "always" and "never" if they are 100% accurate, or you will regret saying those words during the cross examination. Never begin a long answer with the words
"Yes but" or "No but" or you may be interrupted before you can provide your full answer. Instead, begin your response with something like
"That question cannot be answered with a simple yes or no, but..."
Regardless of your personal feelings for the case, remember that you are not the hero, nor the
client's advocate. You must remain professionally impartial, regardless
of your personal feelings, and advocate for the facts. Simply stick to the clean truth and leave the
advocating to the attorney. If the OC doesn't ask the "right" question, the retaining counsel will ensure that the jury gets the facts during redirect.
Especially if those facts were clearly conveyed during the pre-trial
Never become emotional or defensive with the person asking the question, and never guess on things you don't know.
Just state your certainty of what you know as fact. If you are asked a question,
and you don't remember the specific details, never answer that you "don't know". Instead
use the more accurate phrase, "I don't remember". The goal is to tell the truth in as few words as possible and, if there is any awkward silence, that's okay.
Keep in mind that a long-winded answer gives the OC a chance to embarrass
you by saying, "Was that a yes?"
Retain eye contact with whoever is asking the question and then look at the jury during answers that require a longer response. Remain relaxed and confident. Try to keep your body language open (e.g. no crossed arms, clenched fists or angry facial expressions).
The OC may present you with a document during cross in order to invade
your personal space. If timed correctly this can make you anxious, which the jury
could perceive as a lack of confidence. Stay relaxed and, when your opinion is soundly-based, own it with conviction. The goal is to help the
jury's perception of your credibility as they weigh your testimony.