Experts on the stand

Every single day in the criminal and civil justice systems, expert witnesses are testifying in trials and civil depositions. They are all paid witnesses, some very highly paid.

Recently, Dr. Vincent DiMaio testified in the George Zimmerman trial that he was paid $2,400 by the defense. That seems quite reasonable to me. Experts are usually paid for their preparation and testimony. How much they charge depends on their area of expertise, the amount of work that they do and the type of case it is.

In criminal cases, if you have a privately retained lawyer, then you will be responsible for paying out of pocket for any experts that need to be retained. That is unless your lawyer can convince the court that you are indigent and need to have an expert as part of your defense. Each state has rules for this process.

In civil cases, experts are crucial. There is an expert for just about everything. Of course, there are medical experts in personal injury cases. There are experts who testify about whether products are defective or not. There are experts who explain about co-efficient of friction in slip-and-fall cases. The list is endless. When I am doing a mediation in a civil case, one of the most important things for me to know is whether or not each side intends to call expert witnesses.

Each jurisdiction has its own rules regarding expert testimony. According to Federal Rule 702, if an expert is to testify, they have to have the skill, experience, training or education in order to give their opinion or other testimony if:

1. The expert's scientific, technical or other knowledge will help the trier of fact to understand the evidence or determine a fact in issue;

2. The testimony of the witness is based on sufficient facts or data;

3. The testimony is the product of reliable principles and methods;

4. The expert has applied his analysis to the facts of the case.

What this all means is that experts have to help the judge and/or jury understand the evidence or figure out whether a fact is true. Experts have to rely on sufficient facts or data in reaching their opinions. The science involved in their analysis has to be reliable. The problem with polygraphs is that the science behind them has not been determined to be reliable, so polygraph results are not admissible in trial.

Dr. DiMaio testified that he also was a witness in some other high profile cases, including the Phil Spector and Drew Peterson trials. A retired medical examiner, DiMaio is doing what many other professionals do after retirement; they become experts.

In both the criminal and civil legal worlds, attorneys do research to find the right experts for their cases. If you cannot testify and get the point across for your particular side, you won't be giving much expert testimony. If, from an evidentiary standpoint, you cannot reach your conclusion and satisfy the rules, then your opinion will not be coming in.

I have seen a significant number of experts testify. I have heard about fingerprints and DNA so many times that I could almost testify about those topics myself.

In civil cases, it is extremely important that the experts be able to explain things without confounding the jury. I always told the lawyers that jurors were smarter than they give them credit for, but if the explanation is too hyper-technical, then the point will be lost. I have seen some doctors who have jurors eating out of their hands and others who are so arrogant that nothing they say will stick with the jury.

Experts are a necessary part of the legal process. It is up to the jury to decide whether they believe that what the expert is saying is true. In many cases, there is a "battle of the experts."

(Jackie Glass is a lawyer and former district court judge from Las Vegas. You can write to Jackie by emailing You can follow her on Twitter at @theJudgeGlass. This column is being provided for informational purposes only. It may not be relied upon by you as legal advice and does not create an attorney-client relationship.)

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