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Deposition Testimony by Expert Witnesses

Expert witnesses usually must have testimony that remains the same or they could face disqualification from the case and professional problems when others hear of these issues with testimony. Impeaching the witness from the case is important if testimony changes that could impact the case in a negative way to the point of loss.

Can You Impeach an Expert Witness for Having Different Testimony than Deposition Testimony?

During the discovery process, the expert witness may provide an initial statement or report related to or containing testimony about the case. This testimony usually has a basis in fact that also gives opinions about the evidence and tests performed. This initial process generally will help to determine if there is sufficient evidence against a person in a criminal case or to ensure that evidence exists against the defending party. The expert witness provides some type of testimony in this initial stage that may remain broad or specific with less narrow explanations or opinions.

Live Testimony

The court and judge usually want a live testimony for a trial. This requires the expert witness that gave a previous testimony in the deposition stage to also
testify in the trial phase. Sometimes, the expert is not available and the deposition testimony is the only thing available. However, this situation can have use to impeach a witness on the stand and to support the case against the expert witness. There are different standards that will apply, and the judge may still want to hear the professional complete what he or she would say about the case.

The Opposing Legal Counsel

The lawyer on the other side of the argument may use the deposition testimony against the expert witness as grounds to impeach this person. This often depends on the state or federal rules of expert witness use when the trail occurs in one or the other types of courtrooms. These matters also depend greatly on criminal or civil processes. The person seeking a legal remedy or in criminal prosecution can use an expert witness to support and corroborate certain facts. However, when the deposition testimony is different, this often leads to serious complications.

Used Against the Expert Witness

At any point in the trial or hearing, the deposition testimony in part or full can have use against the person that presents it or represents the deposition. When this person testifies as a witness and has involvement in both the case and the deposition, he or she could suffer impeachment when presenting different opinions or facts. The case often requires restrictions that put an expert witness into a box of what he or she can say that is different after the initial stages of the legal proceedings. Because of this, the opposite legal counsel can find grounds to remove the professional.

The Federal Rules of Evidence

Either during a hearing or in the trial itself, the deposition testimony can help impeach an expert witness if he or she was present and gave testimony during this process. The professional can also face impeachment if the Federal Rules of Evidence are in violation because they were present during the deposition testimony. The opposing lawyer can use the deposition for any purpose, and when the current hearing or trial testimony is different, this could lead to a successful challenge for impeachment. The other lawyer can also use it as evidence in the trial if it becomes necessary.

Using the Deposition and the Expert Witness

Because the other lawyer can use the deposition testimony for any reason or purpose, he or she may scan through the previously given testimony to uncover any changes or alterations of the current testimony. By having the evidence against the professional available, he or she can then use the document to impeach the expert witness and suppress the newer testimony from the record. Impeachment could require the other lawyer to hire a new expert witness, but it also causes complications in the case because of this situation.

The expert witness hired by the lawyer will need to seriously consider sticking to the narrow box that the deposition testimony creates even if new evidence or testing methods are available. This important process can limit and inhibit opinions, knowledge about the scene or other aspects of the case that could assist the lawyer in making a successful argument. When only able to present similar testimony, the expert will need to carefully progress through the trial and not let anything new slip or cause confusion because the opinions and facts are in conflict.

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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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