Forensic, General & Medical
Expert Witnesses

Making Objections during an Expert Witness’ Deposition


It is crucial for both the lawyer and the expert witness to understand the objections that could occur during the deposition period. While the opposing lawyer may need this time to object to various issues with the professional, the opposing legal team may also reflect and prepare to counter the objections to keeping the expert witness in the case.

The Objection to an Expert Witness

When an expert gives sworn evidence through a report, testimony or results to a test with other evidence, objections may arise from the opposing legal team. The lawyer that hires the expert may need to prepare him or her to encounter various objections, and this could lead to the professional’s readiness to answer questions and refute the objection based on factual data and information connected to the evidence, testing methods and results that the tests confirm. Challenges to the validity of certain facts or the relevance to the subject material often occur during the deposition period.

The expert will need to reflect on the facts, give answers about the subject material and explain the field of study better when an objection occurs. This may require additional discussion to defend against the initial challenge issued. If the expert must explain damages, he or she may need to discuss the calculations. If the subject regards and accident, the professional may need to walk the judge and opposing legal counsel through each step of reconstruction of the timeline of the incident. This is often necessary for both civil and criminal cases. If the objection is the report, the expert may need to go through each page individually.

Reliability and Testing Methods

When the expert witness proceeds through the deposition, he or she will either give a report or details of relevant testing methods and results with the tests. The initial objections may occur because the testing processes are not those used by similar experts in the same field of study. If this is not a sufficient objection, the legal team may object to the results. When the professional has an error rate greater than five percent or that fluctuates significantly, the end product is not often reliable. This may prove to affect the opinions the expert gives based on the facts and data in the case.

If the lawyer is not able to depend on the reliability of testing methods or the results from error rate fluctuations, the objection may call the expert out. This could lead to exclusion of testimony, exclusion of those results or the disqualification of the professional similar to or proceeding a Daubert challenge. Other objections may arise if the expert witness is not able to clearly explain the subject matter, results or testing methods as with the effect on evidence. Reconstructions that infer certain issues could negatively affect the conclusion. Objecting to these concerns is important when the professional does not appear to know the field well or cannot clearly define certain issues.

Exclusion of Testimony

If the expert is not able to prove he or she is relevant to the case or the testing methods are reliable, the legal team may issue an objection that leads to the objection of testimony. Some cases may exclude certain evidence or the testing itself. If this is the case, the judge may explain to the expert what he or she must do in addition to previous actions. The professional may need to retest evidence or recreate a report. Others may need to try a different tactic entirely. The exclusion could lead to testimony that is inadmissible which does not help the lawyer that hired the expert.

The Burden of Proof

Because the expert witness is only one aspect of a case, he or she may need to prove that his or her expertise and knowledge are relevant to the proceedings. The professional usually has the burden of proof to explain that testing methods do provide a foundation to base opinions on and explain the subject matter. A connection to the test, evidence and results is crucial. However, the burden is primarily observed through the explanation and if any confusion clears up during the deposition with the evidence and details of the case.

Disqualification of the Expert

If the expert is unable to answer or succeed in the objection, he or she may face either exclusion or disqualification. This would relieve the expert of testifying and further involvement in the legal proceedings. For the professional, it is critical to successfully answer the objection.


Provided by HG.org

Disclaimer: While every effort has been made to ensure the accuracy of this publication, it is not intended to provide legal advice as individual situations will differ and should be discussed with an expert and/or lawyer.

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