According to the United States Federal Rules of Evidence (FRE), Rule 702 allows for an expert’s scientific, technical, or other specialized knowledge to help an individual understand the presented evidence and/or determine the factual state of the issue. 

In other words, one might call for an expert opinion to offer a further explanation before a judge in a court of law. Expert witnesses contribute to the credibility of a claim, and it isn’t uncommon for court cases to involve expert testimonies to fortify the factual situation of the concerned party.

What Is an Expert Witness?

An expert witness is someone whose professional opinion molded through training, education, skills, certification, or experience is accepted by a court judge. To be deemed an expert witness, one must fulfill the requirements of the four main pillars comprising the FRE (Federal Rule of Evidence) 702 which we will discuss below.

What Constitutes FRE 702?

Federal Rule 702 concludes that a witness with vital knowledge, skills, experience, training, or education relevant to the matter can be accepted as an expert witness to testify before a judge.

In addition, an expert witness is acceptable under the following circumstances:

  • The expert witness testimony relies on facts and data;
  • The expert’s specific knowledge has resulted from adhering to trustworthy principles and methods;
  • The expert has unbiasedly applied the same methods and principles to conclude the facts of the case in question.

If some criteria aren’t met, the expert witness isn’t admissible.

What Are the Main Pillars that Determine the Admissibility of an Expert Witness?

FRE 702 comprises four main pillars that determine the credibility and admissibility of an expert witness. A potential expert witness must meet the requirements to be deemed an expert witness.


For an expert witness to be admissible in court, they must be part of a profession that is relevant to the case. Moreover, they must also be skilled professionals and have acquired relevant knowledge through practical experience, education, and training. An expert witness can testify only if their expert knowledge and skills clarify the evidence presented before a jury. 


A reliable expert witness possesses enough factual information and data to support their testimony. In addition, reliable expert witnesses also follow principles and methods that are the industry standards of the relevant profession. The court will accept an expert witness’ testimony if they follow their practice’s predetermined standards and use unbiased data to form a testimony.


If an expert witness isn’t adding value to the matter, they should not be deemed an expert witness. An expert’s testimony has to provide a trustworthy opinion to aid the fact-seekers in reaching a conclusion. Moreover, there has to be a reliable scientific connection to the case evidence that was not previously pronounced.


The expert witness’s opinion has to rely on rudimentary facts supported by other experts in the field relevant to the case. The facts that the expert relies on to form their statement must be authentic, credible, and relevant to the case in question. 

Contact Alpine Engineering For Trusted Mechanical Expert Witnesses

If you ever need an expert witness to inform your case, trust us at Alpine Engineering to offer a list of mechanical engineers with experience and expertise.  When our mechanical engineering expert witnesses agree, they will provide credible opinions supported by facts, data, testing, and trustworthy principles and methods

Our licensed engineers are geared up on years of experience and relevant knowledge, so whenever you need us, just get in touch – we’ve got you covered.