Expert Witness

Evidence used to resolve legal issues falls within several classes: physical evidence, demonstrative evidence, documentary evidence, and testimonial evidence, to name a few examples. Testimonial evidence comes in at least two different forms – eyewitness testimony and expert witness testimony. Expert witnesses offer professional opinions on issues that are relevant to a case.

How Do Lawyers Use Expert Witnesses in Personal Injury Cases?

Lawyers use expert witnesses for many purposes, including:

Some experts work full-time as witnesses and derive 100% of their income from this role.

What Happens When Expert Witnesses Contradict Each Other?

What Happens When Expert Witnesses Contradict Each Other?

In many cases, each side will call their own expert witness. The testimony of these witnesses will likely be inconsistent and will likely reflect the disagreement between the parties. When this happens, it is up to the jury to decide which expert to believe. Rarely, a judge will overrule the decision of a jury on which expert witness to believe. When judges do this, an appeal is likely.

What Qualifications Do Expert Witnesses Need?

You cannot recruit the “average Joe” off the street as an expert witness. An expert witness must demonstrate advanced knowledge about the field in which they will testify. Florida Rule of Civil Procedure 1.390 sets out the general qualifications of an expert witness. Some of the more specific qualifications include:

  • Academic qualifications (a professional degree is a necessity, for example);
  • Professional experiences;
  • Publications in respected academic journals;
  • Awards given by professional peers;
  • Experience testifying (the ability to think clearly during cross-examination is a storing asset);
  • Reputation; and
  • Name recognition.

An expert does not need all these qualifications. Many respected experts enjoy no name recognition outside their fields, for example. The foregoing qualifications, however, either help the expert perform better in court or bolster their credibility with the jury.

How Courts Qualify Expert Witnesses

Fla. Stat. §90.702 requires that a potential expert witness meet a number of criteria before they can offer a professional opinion in sworn testimony. 

The Subject Matter is Appropriate for Expert Testimony 

An expert’s testimony must help the jury understand the evidence or determine a contested fact. The expert’s testimony must be based on a reliable body of scientific or other specialized knowledge. If no such body of knowledge exists, the expert may not testify. 

The Witness is Qualified as an Expert

The court must determine whether the witness is qualified to express an opinion on the matters to which they will testify. Even if so, the expert’s comments must be restricted to their field of expertise.

The Ultimate Decision

Ultimately, it is up to the trial judge to accept or reject someone as an expert. If the judge rejects the expert as unqualified, the expert may not testify. The side that attempted to call the expert witness, however, can use the trial court’s rejection of the witness as grounds for an appeal.

Compensation of Expert Witnesses

Expert witnesses usually require significant financial compensation. The opposing party might seek to use the fact of compensation to discredit the expert witnesses’ testimony in the eyes of the jury. Nevertheless, compensation of expert witnesses is routine in trial proceedings.

Who Pays the Expert’s Fee?

Most personal injury lawyers will pay the expert’s fee themselves and deduct it from any compensation that you receive. If you receive no compensation and you are operating under a contingency fee agreement with your lawyer, you will pay nothing – either in legal fees or expert witness fees.

Expert Witnesses Outside of Court

Lawyers use expert witnesses outside of court under the following circumstances:

Florida’s Medical Malpractice “Reasonable Investigation” Requirement

Florida courts require you or your attorney to certify that you have conducted a reasonable investigation of your medical malpractice claim and that you have a good faith belief that your case is sound. One way of establishing this is to file a written opinion from a medical expert stating that your claim has merit. The purpose of this rule is to discourage frivolous medical malpractice lawsuits.

Settlement Negotiations 

The statement of a credible expert witness can influence settlement negotiations, before or after you initiate a formal lawsuit. Even a written report offered by an expert witness can result in a settlement.  


Depositions are out-of-court proceedings that take place after the commencement of a lawsuit but before trial. Lawyers question witnesses under oath and the court supervises the process. Lawyers typically record the proceedings so that if an expert witness offers courtroom testimony that is inconsistent with their deposition testimony, the opposing lawyer can use the discrepancy to discredit the witness. 

When to Use an Expert Witness

You don’t need an expert witness in every kind of personal injury case. Expert witnesses are a necessity, however, in certain kinds of cases, such as medical malpractice claims. Consult with your lawyer if you think you might need an expert witness.