Expert Opinions and Lay Opinions

In a courtroom there are two types of opinions: (1) lay opinion, and (2) expert opinions.  If the opinion is relevant, then it should be admissible.  Let’s take a look at each one.

Lay Opinion

I like to equate lay opinions to an opinion my mother (a retired administrative assistant for a school system) could give in a case.  For instance, if the demeanor of the defendant was relevant, then if my mom observed the defendant to be very angry, she could testify that he appeared angry … in her opinion.  Basically, a lay opinion is one that anyone can give based on their observations.

Expert Opinion

Experts are oftentimes views as limited to some scientist with some fancy degree or title.  However, an expert can form an opinion based on “knowledge, skill, experience, training or education.”  And that “or” is very important as any one of the five preceding backgrounds can make one an expert.

Example

Let’s suppose that a prosecutor is pursuing a case where, on a traffic stop, the suspect is found to be in possession of three 1/8 ounce packages of methamphetamine, along with some scales and a cutting agent.  The issue at trial is whether this individual is simply a drug user or if the facts point to the person being a drug dealer.  That quantity may not look like a lot to my mother or her peers who would comprise the jury.  So, think of your experienced narcotics officer.  Compared to my mother, would this officer have knowledge relevant to drug dealing that my mother wouldn’t have – of course. The same could be said for skill, experience, training, and possibly education. So that officer would qualify in each of the 5 categories.  Suppose the street value of the drugs was at issue (which courts have said are relevant to show distribution activity).  The prosecutor would not call some economics professor to prove the value, but the value of street drugs ultimately comes from a drug offenders.  If cops know the value, its only because users and dealers have told them in interviews or while the officer was undercover.

The Takeaway

Officers should testify as an expert each and every time – and officers potentially would qualify in virtually every category allowed under the evidence code.  How an officer can articulate his or her expertise and the court recognition of expertise will be addressed in subsequent sessions.

Legal Supplement

12 O.S. Section 2701

Opinion Testimony by Lay Witnesses

If the witness is not testifying as an expert, the witness’s testimony in the form of opinions or inferences is limited to those opinions or inferences which are:

1. Rationally based on the perception of the witness;

2. Helpful to a clear understanding of his testimony or the determination of a fact in issue; and

3. Not based on scientific, technical or other specialized knowledge within the scope of Section 2702 of this title

12 O.S. Section 2702

Testimony by Experts

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 in the form of an opinion or otherwise, if:

1. The testimony is based upon sufficient facts or data;

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

3. The witness has applied the principles and methods reliably to the facts of the case.