Expert Testimony: What They Say, Why They Say It and Why the Courts Cannot Do Without Them.

The identification of an expert in a criminal or civil case is a big deal. The witness is called to the witness stand and the lawyer calling the witness begins asking questions to let the jury know about the background, training and experience of the witness. The witness turns toward the jury and speaks about his education, work experience or training. The lawyer then formally tenders the expert to the court. “Your honor, I tender Mr. Smith as an expert in the area of….” If the court accepts the witness as an expert, he is able to educate the jury on matters “beyond the ken”  or understanding and knowledge of the average juror. This is a critical point in any trial.

So who are these experts and where do they come from? What do they tell the jury? Does the jury listen and more importantly, why do we need them? In order to answer these questions, we need to look at the role of the jury and who sits on juries.

In a trial, the jury sits as the fact finder and the judge determines the law applicable to the case. This means that the jury will review and hear the evidence and decide what weight, if any, they will give to the documents, witnesses and other items introduced and allowed into evidence by the judge. In the course of the trial, there will be concepts that require specialized knowledge to understand. For example, in a DUI trial, a jury may need to learn about a prescription medication in order to determine if it would impair a person when driving a car. However, the law does not require jurors to have any specialized knowledge in order to sit on the jury. Jurors have varying degrees of education from grade school to graduate school. In order to ensure that the jurors can understand all of the evidence, the law allows experts to testify about these specialized issues to help the jury decide what weight, if any, to give the evidence.

Who Are These Experts?

Experts come from all areas of society. They are university professors, scientists, authors, licensed professionals and skilled workers who have been doing the same job for 20 years. It all depends upon the evidence at issue in the case. An expert in a vehicular homicide case may be an accident reconstructionist or an engineer to talk about the effects of poorly maintained brakes. An expert in a homicide trial may be a medical examiner or a DNA researcher. The standard for an expert varies slightly from state to state. The standard used in federal courts is found at Rule 702 in the Federal Rules of Evidence:

Rule 702. Testimony by Expert Witnesses

A witness who is qualified as an expert by knowledge, skill, experience, training, or education may testify in the form of an opinion or otherwise if:

(a) the expert’s scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine a fact in issue;

(b) the testimony is based on sufficient facts or data;

(c) the testimony is the product of reliable principles and methods; and

(d) the expert has reliably applied the principles and methods to the facts of the case.

This standard is applied in all cases including allegations of excessive force by LEOs. In such a case, the law recognizes that the jury is not expected to know about use of force techniques, law enforcement tactics, options available to LEOs when faced with threats and law enforcement procedures. In these cases, the experts could be LEOs with many years of experience as trainers, street officers and administrators.

How Do Experts Form Their Opinions?

An expert can rely on just about anything to form and support his opinions. From incident reports to policies and procedures as well as research done by others, the expert is entitled and expected to consider all available information from every source. In fact, the expert is expected to consider the theories of the opposing side in a case and can be asked if those theories are viable.

Experts also form their opinions based upon their experience. For instance, a firearms expert may testify how LEOs are trained to use cover or reload during a firefight. A defensive tactics expert may testify about the ability of a LEO to effectively use hard hand techniques following a foot chase. Finally, a LEO with many years of street experience may testify about the reasonableness of handcuffing all suspects behind their backs.

Does The Court Really Need Experts and Does The Jury Really Listen To Them?

Like the expert who brings his experience to the trial, the jurors also bring their own experiences to the courtroom. This can be helpful or harmful. A juror who only knows about police procedure from watching T.J. Hooker will likely not make good decisions! Likewise, a juror who has watched every episode of CSI may not understand what she does not know about the realities of a criminal investigation. Therefore, the court and the jury need experts, especially in a case involving the use of force by LEOs.

In my experience, the jury usually pays attention to experts. Even if they do not completely agree with  their opinions, they place a great deal of weight on the person who is brought to the court without an agenda and is accepted by the court as a person having specialized knowledge. They will listen to the expert. That is all you can ask because if they listen, they may learn enough to help them reach a decision.

Be Part Of The Solution

So here is the take away. First and foremost, tell everyone you know to consider jury duty an honor. It truly bothers me when I hear people talk about getting out of jury duty. We need reasonable people on juries. As a LEO, your career and freedom could depend upon it.

Second, consider acting as an expert. If you have information that would help a jury, if you can speak plainly with strangers to educate them about police procedure and if you enjoy the courtroom, you could be an effective expert.

Stay safe.


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