Defining An Expert Witness
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What Is An Expert Witness?

Are you interested in the services of an expert witness or becoming an expert witness yourself? Here is everything you need to know.

This article will cover the following:

Keep reading for full details.

Expert Witness Defined

An expert witness is hired to provide independent expertise on any subject in a court of law. Expert witnesses can be used in various capacities like arbitrations and litigations. These witnesses will give sworn evidence to a court of law or tribunal.

There are two types of expert witnesses:

  1. Witness who gives evidence based on his/her expertise related to the facts of a specific case.
  2. Witness of fact who provides evidence, but generally refrains from giving opinions.

Anyone with knowledge or expertise in a field of interest can become an expert witness. The main duty of any expert witness is to provide the court with unbiased expertise and opinions related to the case. These experts are called upon to help decide disputes. Typically, witnesses are not used to assist in the formation of a party’s claim or defense, though. Testimonies by these witnesses can ultimately swing juries and win cases. Expert witnesses will always be compensated by the team retaining them.

Expert Witness Duties

An expert witness will perform the following tasks:

  • Provide an independent expert opinion in their area of expertise.
  • Provide the opinion in the form of a report and/or evidence before as required.
  • Comply with the specific procedure rules applicable and any court orders in the case.
  • Provide truthful, impartial and independent opinions.
  • An expert witness has an overriding duty to the Court.
  • The Court expects an expert witness to be independent and impartial.

An expert witness will NOT perform the following tasks:

  • Be your advocate and argue your case, nor will they find evidence or suggest what your case should consist of.
  • Provide any opinion beyond their area of expertise.
  • Accept any appointment which involves a conflict of interest.
  • Accept any appointment on terms that are conditional on the outcome of the case. 
  • Act as a negotiator.

Types of Expert Witnesses

Types Of Expert Witnesses

There are many different kinds of expert witnesses, including:

Medical Experts

  • Pain and suffering caused to an individual
  • Insight into additional surgeries that may be needed
  • Prognosis for the person
  • Limitations the people may face following an injury
  • The effects of injuries following a criminal assault
  • Ascertaining whether great bodily harm of substantial bodily harm has been caused
  • Explain the manner of death following a homicide

Vocational Experts

  • Whether a person can return to the workplace and under what conditions
  • Advise to what additional training a person may benefit from to facilitate their return
  • What a person may do to reclaim their independence
  • Testify to how much future wages may be lost
  • Investigate and offer advice as to how long alimony should last

Engineering Experts

  • The safe design and manufacture of a product
  • Whether the designer or manufacturer was aware of a defect that may cause injury when used in the intended manner.

Forensic Experts

  • Establishing DNA evidence
  • Ascertaining if a substance is an illegal substance
  • Testifying about the level of alcohol found in blood
  • If a fire was deliberate or the result of an accident

Mental Health Experts

  • If someone was in a rational state of mind when making changes to their will
  • Is there a question of criminal insanity
  • Does a person have full mental competency or not?
  • Is a person mentally capable of managing their own affairs

Parenting Experts

  • Advising on the emotional capacity of a child or children
  • If a parent is in recovery from addiction whether or not they can be effective parents
  • Evaluating the home life of a child or children
  • Recommending course of actions and plans in the best interest of the child or children

Benefits Of Expert Witness Testimony

The benefits a well-chosen expert witness provides to a case aren’t all apparent at first glance. Here’s why expert witnesses are important – and why selecting the right expert is vital. Popular images of “experts” often include people who make their living at a particular practice or topic, or who have written a book on the subject. Yet legal standards for experts don’t require that expert witnesses meet either of these standards. 

This flexibility can be of great use to attorneys. The central issue in some cases is so narrow and fact-specific that no one makes their living by focusing solely on that particular issue.  At the other end of spectrum, some cases present issues that cannot be fully understood unless their impact in several different domains is explored. For example, establishing the full impact of chronic pain after a car accident may require attorneys to explore several different areas of medicine, including neurology, orthopedic medicine, physical and occupational therapy, and psychiatry or psychology

Preparing a lay witness to testify is often a matter of ensuring they understand the basic boundaries of lay testimony. Experts are educated and/or trained in their particular specialty area, they can take what they know and build on it. Because they have the opportunity to objectively interpret the facts from using a variety of methods, experts can develop a cogent analysis of the liability on which to base their testimony.

Can Anyone Become An Expert Witness?

If you are wondering if any professional can become an expert witness, the answer is yes. In fact, nowadays many nurses, doctors and paramedics are commonly called for services during cases. These professionals are called to provide expertise on injuries, medical procedures, etc. Many other professions can be in high demand, as well. For example, contractors and architects are used to provide insight on building codes and construction practices, among other topics. Teachers can be requested in cases regarding education.

These are the legal expectations for all expert witnesses:

  • Agree contractual terms with the expert in writing before the work is started. These will include terms of payment. Many experts use standard terms such as The Academy of Experts ‘Model Terms of Engagement For The Employment of Experts.’
  • Provide detailed instructions.
  • Keep the expert informed of developments in the case and of all key dates in good time.
  • It is better that the legal representative, if you have one, deals with the Expert rather than you doing so.

Expert Witness Legal Standards

There are no “hard and fast” rules or regulations for expert witnesses today. Instead, attorneys and judges rely on two monumental court opinions when determining whether or not a witness is qualified for the case. Frye Vs. The United States essentially established standards for expert witnesses. The ruling in the case stated that any witness testimony must be widely accepted within the scientific community.

A different case, Daubert Vs. Merrill Dow Pharmaceuticals, Inc., resulted in a more modern set of standards. As long as the witnessed used scientific methods, peer-reviewed methodology and shared an opinion that was widely accepted, the expert’s opinion would then hold up in court. The Daubert case essentially gave judges the power to determine validity of any expert testimony.

When Are You Officially An Expert Witness?

There are several ways to become recognized as an expert witness either through extensive education or job-related experience. Typically, there are a few guidelines that hold true in the majority of cases utilizing their services. Witnesses ideally hold a terminal or advanced degree in their professional field. In some cases, a long and successful career can outweigh academics, though.

Attorneys determining the validity of an expert witness will examine these areas:

  • Have you at any time been quoted by the press?
  • Have you spoken at any professional conferences?
  • How flexible is your current schedule?
  • Have you ever won a prestigious award?
  • Is any work of yours published in highly-regarded journals?
  • Do you have any prior witness experience?
  • Are you comfortable and able to communicate during court proceedings?

Expert Witness Fees

When retaining an expert witness for a case, the lawyer usually negotiates a contract between the two professionals with certain aspects of financial matters that will detail the fees involved and what the expert witness can expect in payment. On average, the services of an expert witness will cost $350 per hour, with fees ranging from $275-$500 per hour.

Expert Witness Cost

Here are the fees associated with the services of an expert witness:

  • Agreement fees.
  • Engagement fee.
  • Consultant fee.
  • Travel fees.


Real Estate Expert Witness Services by Craig Cherney, Esc.

Craig Cherney is a trusted client advisor and a sought after real estate expert witness who is hired by the nation’s top Real Estate Litigation Attorneys to help resolve their litigated real property matters.  Craig has appeared as a testifying expert witness before judges and juries in California, Arizona, Nevada and other jurisdictions across the country. Craig Cherney, Esq. Expert Witness Real Estate480-399-2342.