Expert Witnesses

Prior articles discuss the way a lawsuit is started and the discovery stage of a lawsuit that takes place between the initial filing of court papers and the trial. The purpose of a trial is to allow a fact finder (either a judge or jury, depending on the type of case) to make determinations of the facts, apply the law to those facts and make a decision in favor of one party or the other.

Sometimes the case deals with facts in a specialized area that is outside the common knowledge of the judge or jury.  For example, a judge or jury is not likely to be have enough knowledge of medicine to determine how badly a person was injured in a car accident, or to determine if the conduct of a lawyer arises to the level of legal malpractice, or to determine if the chain saw that injured someone was improperly engineered and unsafe for use.   When a case deals with facts that are outside the common knowledge of a judge or jury, the parties to the lawsuit hire experts in that field of knowledge who will educate the fact finder at trial.  These expert witnesses are allowed to render an opinion based on their particular area of expertise. 

Expert witness testimony is permitted to be submitted at trial by an evidence rule that states:

If scientific, technical, or other specialized knowledge will assist the trier of fact to understand the evidence or to determine a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify thereto in the form of an opinion or otherwise.

A person qualifies to be an expert only if it can be demonstrated that the person through education and/or experience has achieved a thorough knowledge of a specialized area such as some science, profession, business, process or occupation. 

Before the trial, during the discovery stage, the expert has to prepare a report stating the expert’s opinion and lays out all the facts on which the opinion is based.  The report also needs to explain enough about the specialized area to demonstrate that the opinion is based not just on the expert’s opinion, but on generally accepted principals in that specialized area.

For example, if an engineer is to provide an expert opinion that the contractor was at fault for the collapse of the outside deck that the contractor built, the engineer would need to have been educated in the area of construction engineering and have experience in construction.  The engineer would need to look at how the contractor built the deck and then point out what the contractor did wrong.  The engineer can not merely say, “well, based on my experience, the contractor should have used more nails.”  Instead, the engineer must say, “the contractor did not use the correct number of nails as was necessary to support a deck of this size.  Using engineering math, and based on engineering treatises and manuals that are used in the universities to train engineers, and municipal construction codes, a deck of this size required ten nails for every three feet and this contractor used only six nails for every three feet.  This created excess pressure on the boards causing the deck to collapse.”

Of course, lawyers say you can always find an expert to give you a complete contrary opinion.  In the deck case, the attorney for the contractor will surely find an engineer to testify that based on new advances in nail technology, only six nails were necessary and the reason that the deck collapsed is because of termites that were not the fault of the contractor.

Experts cost money and parties to a lawsuit often settle a case before that stage of the lawsuit where it becomes necessary to lay out the money to hire the expert.  If the case does not settle and an expert is necessary, a party wants to get the best expert available.  A case often turns on which expert the jury finds to be more believable and more reliable. 

Look for other blog posts on the topics of Discovery, Legal Malpractice, Mediation, Non-Binding Arbitration and the Trial. 

This article is intended as general information and not as legal advice.  If you are considering starting a lawsuit, contact an attorney at Maselli Warren, P.C. to schedule a consultation.