An Expert Witness' Perspective on Depositions

By Mike Wakshull

Taking the deposition of an expert

As a lawyer, you may find that the expert you’re deposing has been deposed many more times than you have taken a deposition. A good first questions to ask an expert is, “How many times have you been deposed?” The answer to this question sets the next series of questions.

The next question should be, “Are you familiar with the standard admonitions and instructions for taking the deposition?” If the answer is yes, you can usually skip asking questions such as the difference between a guess and an estimate. The phrasing of this question is important. Once an attorney asked me whether I knew her rules for taking a deposition. My answer was “No.” The attorney proceeded to spend at least 15 minutes going over standard admonitions and protocol.

Several years ago, an attorney offered excellent advice about garnering information from another party. He said, “You catch more flies with honey than with vinegar.” This is sage advice for taking a deposition. Greet the deponent in a friendly manner. During the deposition speak in a conversational tone. The experienced deponent knows you are not attempting to be their friend, yet they are likely to offer the information you seek.

Using a harsh tone and attacking the deponent may cause them to withdraw and not offer the information you seek.

Work closely with your expert to craft questions of the opposition’s expert witness, as your expert is more knowledgeable in the subject matter of the deposition than you. You may find they are also knowledgeable about the strengths and weaknesses of the deponent.

Use available tools such as LEXIS-NEXIS and Find Law to learn valuable information about the deponent’s background and other cases they’ve worked on. Read prior depositions carefully. You may discover that the deponent’s answers to your questions contradict their answers provided during previous depositions.

An experienced witness knows to answer only the question asked. Deposing attorneys must carefully craft their questions to obtain the desired information. Following is an example of an attorney seeking to learn whether the experienced expert was qualified to work on a case.

Attorney:         “Did you use infrared to examine document?”

Deponent:       “No.”

Attorney:         “Why did you not use infrared to examine the document?”

Deponent:       “The budget was not there.”

Attorney:         “Do you have equipment to examine the document using infrared?”

Deponent:       “No.”

In this exchange, the attorney questioned the deponent in a very conversational, nonthreatening manner. The deponent answered only the questions asked. His response about the budget was misleading. The attorney revealed this by asking if he owned the infrared viewing equipment.

As a result, the deponent revealed to the attorney he had taken a job for which he was not qualified.

The attorney asked these questions because his expert witness knew the opposing expert did not own the required equipment.

Paying the expert’s fee

Although Code of Civil Procedure requires payment for the anticipated deposition time prior to start of deposition, it is generally accepted practice to pay the expert at the end of the deposition for the full testimony time. Prior to writing a check, ask the expert to whom it should be made payable.

Preparing your expert for deposition

Regardless of how many times your expert has been deposed, it is imperative for you to prepare your witness. Preparation includes asking your expert questions exposing their weaknesses and potential weaknesses of the case. Coach the witness how to answer these questions in a manner that least harms your case or damages the expert’s credibility.

Preparation should include a mock deposition. Ask the tough questions. Ask your expert to reveal weaknesses in their opinion and methodology. Ensure they do not appear defensive or argumentative when answering tough questions.

Most depositions require the deponent to produce their entire case file. This includes all work product, notes, and communications with attorneys and other parties who may have been consulted for the case. The Code of Civil Procedure requires production at least three days prior to the deposition.

You need to review all material being produced before it is provided to the opposing side. Make sure the production is compliant with the demand. If some items in the demand will not be produced, discuss this with your expert. As an example, I have been asked to produce transcripts from all prior testimony. This has never been produced.

To control your costs, ask the expert to upload the electronic work product to Dropbox or another cloud-based storage location. You can provide the deposing attorney with a link to the folder.

With your expert, share only information they need in order to understand the portion of the case they are working. Take care not to unintentionally bias the expert’s perception of the case by sharing too much. For example, a document examiner should not be told whether your client believes a writing is falsely attributed to them. The document examiner only needs to know that a writing must be authenticated to determine whether it is attributable to a particular person. If unnecessary confidential facts about the case are shared with your expert, these facts may be shared while answering a deposition question, thus exposing your strategy.


Whether you are preparing to depose an expert witness or preparing your expert to be deposed, it is incumbent to work with your expert witness to understand the strengths and weaknesses of the case. You must also know the strengths and weaknesses of both experts.

Some attorneys ask questions during deposition that essentially cross-examine the expert. Other attorneys ask questions attempting to reveal information to ask during cross-examination at trial—information that may discredit the expert or reveal flaws in their opinion or methodology.