Difference Between Lay Opinion Testimony and Expert Opinion Testimony

Posted by David Adelstein on April 07, 2016
Appeal, Evidence, Standard of Review / Comments Off on Difference Between Lay Opinion Testimony and Expert Opinion Testimony


Although I have numerous blog articles regarding the appellate standard of review when it comes to the admissibility of evidence, it is important to remember that “[a] trial court’s ruling on the admissibility of evidence is reviewed for an abuse of discretion; however, the trial court’s interpretation of the evidence code is reviewed de novo.” L.L. v. The State of Florida, 41 Fla.L.Weekly D854a (Fla. 3d DCA 2016).

In L.L., a criminal case, a police officer testified that he smelled the strong odor of marijuana from the defendant and that a plastic bag in defendant’s possession contained marijuana. The defendant objected that the officer’s opinions about the smell being marijuana and the substance in the bag being marijuana was an improper lay opinion and constituted expert opinion testimony (governed by the Daubert standard). The trial court allowed this testimony and the issue on appeal was whether such testimony was expert opinion testimony or proper lay opinion (fact witness) testimony.

The appellate court held that the officer’s testimony or opinions about the smell and substance being marijuana was proper lay witness opinion testimony governed under Florida Evidence Code 90.701:

If a witness is not testifying as an expert, the [lay] witness’s testimony about what he or she perceived may be in the form of inference and opinion when:

(1) The witness cannot readily, and with equal accuracy and adequacy, communicate what he or she has perceived to the trier of fact without testifying in terms of inferences or opinions and the witness’s use of inferences or opinions will not mislead the trier of fact to the prejudice of the objecting party; and

(2) The opinions and inferences do not require a special knowledge, skill, experience, or training.

The appellate court’s holding included a very good discussion explaining in detail why the officer’s opinion was proper lay opinion testimony as opposed to expert opinion testimony governed by the Daubert standard:

In addition to the requirement that lay opinion testimony be based on the personal knowledge and perception of the witness, the Advisory Committee Notes explain that courts should consider the witness’s method of reasoning: “the distinction between lay and expert witness testimony is that lay testimony ‘results from a process of reasoning familiar in everyday life,’ while expert testimony ‘results from a process of reasoning which can be mastered only by specialists in the field.‘ ” …As one scholar has explained:

[T]he distinction lies in whether the witness’s reasoning process entails a reliable methodology beyond everyday reasoning. A lay witness, however experienced, offers no methodology beyond ordinary reasoning. An expert is equipped to draw more sophisticated, yet still reliable, inferences. The crux of expert testimony is that it presents inferences that are supported through the application of a reliable methodology. Thus, the witness who relies on experience to support an expert opinion cannot simply claim insights arrived at by applying everyday reasoning to that experience base, but must explain the methodology employed to reach that opinion. An experienced witness who does not bring such methodology to bear should be subject to the restrictions of the lay opinion rule.


One important reason the Daubert standard [governing the admissibility of expert witness opinions] imposes a more demanding reliability inquiry upon expert opinion testimony is that the opinion results from a methodology or reasoning process that might be foreign to the trier of fact….But in cases such as the one now before us, even if the trier of fact does not have the personal experience necessary to identify the substance in question, the reasoning process is not “foreign in kind.” Many people who have seen and smelled marijuana would be able to recognize it in the same way they recognize anything else they have seen or smelled before.


Here, Officer Munecas’s reasoning process is nothing that requires a specialist in the field of drug identification; it is reasoning familiar in everyday life.


Finally, we hasten to add that although the more demanding Daubert admissibility standard does not apply to lay opinion testimony, there is nevertheless a reliability inquiry. Not only must lay opinion testimony be based on the witness’s personal knowledge, section 90.604, Florida Statutes, and perceptions, section 90.701, Florida Statutes, but the witness must have sufficient personal knowledge to support the opinion.

L.L., supra (internal citations omitted).

Please contact David Adelstein at dadelstein@gmail.com or (954) 361-4720 if you have questions or would like more information regarding this article. You can follow David Adelstein on Twitter @DavidAdelstein1.

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Make Sure to Timely Raise Your Daubert Objection to Expert Testimony

Posted by David Adelstein on March 09, 2016
Evidence, Expert Testimony / Comments Off on Make Sure to Timely Raise Your Daubert Objection to Expert Testimony


If you are going to raise a Daubert objection or challenge (or request a Daubert hearing), you need to TIMELY do so before the expert witness testifies. A Daubert motion / challenge / hearing relates to the admissibility of an expert witness’ testimony. As you can imagine, this is an extremely important issue as many cases depend on expert witness testimony to support their burden of proof.

In Rojas v. Rodriguez, 41 Fla.L.Weekly D423a (Fla. 3d DCA 2016), a defendant raised a Daubert objection post-verdict. The defendant was challenging the admissibility of the testimony of plaintiff’s neurosurgeon expert in requesting a new trial. The trial court granted the defendant’s motion. On appeal, the appellate court reversed ordering the reinstitution of the jury’s verdict because the defendant did NOT timely raise its Daubert objection:

Moreover, it was incumbent upon the defendant, as the challenging party, to timely raise a Daubert objection and request a hearing before the trial court. Given the trial court’s role as “gatekeeper” in the Daubert context, it stands to reason that such an objection must be timely raised to allow the trial court to properly perform its role:…


Here, there was no timely Daubert objection, nor is there any indication that exceptional circumstances existed to merit consideration of the defendant’s untimely objection. As such, the trial court erred in granting the defendant’s motion. Accordingly, we reverse the order on appeal and remand so that the trial court may reinstitute the jury’s verdict. Because the defendant failed to make a timely Daubert objection, we do not reach the issue of whether the neurosurgeon’s testimony would have been admissible under Daubert.

Please contact David Adelstein at dadelstein@gmail.com or (954) 361-4720 if you have questions or would like more information regarding this article. You can follow David Adelstein on Twitter @DavidAdelstein1.

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Expert Opinion Testimony and the Standard of Appellate Review

Posted by David Adelstein on January 11, 2015
Appeal, Expert Testimony, Standard of Review / Comments Off on Expert Opinion Testimony and the Standard of Appellate Review


Previously, I discussed expert opinion testimony and the Daubert gatekeeping test employed by trial courts to determine the admissibility of the expert testimony. But, there is much more to expert opinion testimony. 

An expert witness is NOT allowed to serve as a conduit for inadmissible hearsay so that a party is using an expert witness to simply get in testimony/evidence that is otherwise inadmissible. Doctors Co. v. State, Dept. of Ins., 940 So.2d 466, 470 (Fla. 1st DCA 2006) (“The rule is well established that if an expert is called merely as a conduit to place inadmissible evidence before the jury, the trial court appropriately exercises its discretion by excluding such evidence.”); accord Tolbert v. State, 114 So.3d 291, 294 (Fla. 4th DCA 2013) (internal quotation and citation omitted) (“Although an expert may rely on hearsay in reaching the expert’s opinion, an expert’s testimony may not merely be used as a conduit for the introduction of the otherwise inadmissible evidence.”)

Moreover, an expert is NOT permitted to bolster his/her credibility on direct examination by testifying that he/she relied on communications/consultations (hearsay) with other experts in order to reach his/her expert opinion. See Linn v. Fossum, 946 So.2d 1032 (Fla. 2006). Stated differently, an expert cannot bolster his/her credibility by testifying that a treatise, article, study, or colleague (e.g., hearsay) agrees with his/her opinion before the expert has been impeached on cross-examination. See Duss v. Garcia, 80 So.3d 358 (Fla. 1st DCA 2012).

What if the trial court allows or disallows expert testimony? In other words, what if the trial court grants a motion to strike an expert (or certain expert testimony) or denies a motion to strike an expert (or certain expert testimony)? 

“The standard of [appellate] review for trial court decisions concerning the qualifications of expert witnesses and the scope of their testimony is abuse of discretion.”   County of Volusia v. Kemp, 764 So.2d 770 (Fla. 5th 2000) (reversing final judgment because trial court erred in allowing expert opinion testimony). This means that a trial court’s acceptance of expert opinion testimony or rejection of expert opinion testimony will NOT be disturbed on appeal unless the trial court abused its discretion. Doctors Co., 940 So.2d 466 (finding the trial court did not abuse its discretion in disallowing expert testimony).


Please contact David Adelstein at dadelstein@gmail.com or (954) 361-4720 if you have questions or would like more information regarding this article. You can follow David Adelstein on Twitter @DavidAdelstein1.

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Expert Opinion Testimony and Understanding Daubert’s Gatekeeping Test

Posted by David Adelstein on January 10, 2015
Evidence, Expert Testimony / Comments Off on Expert Opinion Testimony and Understanding Daubert’s Gatekeeping Test

Expert opinion testimony

Expert opinion testimony is an important aspect of complex civil litigation. Expert testimony assists in proving or disproving liability and damages. A credible and persuasive expert can make the difference in a case and retaining experts, generating expert opinions, and the manner in which expert opinions are presented should not be taken lightly.

Regarding expert testimony, Florida Statute s. 90.702 provides:

“If scientific, technical, or other specialized knowledge will assist the trier of fact in understanding the evidence or in determining a fact in issue, a witness qualified as an expert by knowledge, skill, experience, training, or education may testify about it 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.”

Not all expert opinion testimony is admissible. Courts are required to employ a gatekeeping function to ensure that expert opinion testimony is reliable before that testimony is admissible. This way unreliable expert testimony is not considered by the jury.



Florida courts now apply what has been referred to as the Daubert test to determine the admissibility of ALL expert testimony. See Perez v. Bell South Telecommunications, Inc., 138 So.3d 492 (Fla. 3d DCA 2014). This test arose out of the United States Supreme Court’s decision in Daubert v. Merrell Dow Phamaceuticals, Inc., 509 U.S. 579 (1993) and has been the gatekeeping test applied to expert testimony in federal courts.   This Daubert test forms the basis of a court’s gatekeeping function regarding the admissibility of RELIABLE expert opinion testimony.

How does a party offering expert opinion testimony satisfy its burden of establishing the reliability of the testimony? Parties need to know this because it is common for parties to file a (Daubert) motion attacking the reliability of another party’s expert testimony.

The Eleventh Circuit Court of Appeal explained:

“Courts must engage in a rigorous inquiry to determine whether: (1) the expert is qualified to testify competently regarding the matters he intends to address; (2) the methodology by which the expert reaches his conclusions is sufficiently reliable as determined by the sort of inquiry mandated in Daubert; and (3) the testimony assists the trier of fact, through the application of scientific, technical, or specialized expertise, to understand the evidence or to determine a fact in issue.”

 Rink v. Cheminova, Inc., 400 F.3d 1286, 1291-92 (11th Cir. 2005) (quotation omitted).



The first factor focuses on the qualifications of the expert. The expert needs to have some qualifications in order to render his/her expert opinion. Sometimes, however, parties hire experts with minimal qualifications. Federal courts have found that this goes to the expert’s credibility at trial and not the admissibility of the expert’s opinion. See Feliciano v. City of Miami Beach, 844 F.Supp.2d 1258 (S.D.Fla. 2012). This means that the other party can impeach the expert’s credibility at trial based on the expert’s minimal qualifications in order to create the appearance that the expert is not a credible or reliable witness.



The second factor focuses on the reliability of the expert’s opinion. Just because a witness is qualified to render an opinion does NOT mean the opinion is reliable. A judge has a degree of leeway in determining the reliability of the opinion by focusing on certain nonexclusive factors such as “(1) whether the expert’s methodology can be tested; (2) whether the expert’s scientific technique has been subjected to peer review and publication; (3) whether the method has a known rate of error; (4) whether the technique is generally accepted by the scientific community.” Rink, 400 F.3d at 1292.

This second factor is the crux of the Daubert test. See Fla. Stat. s. 90.702.   To this point, Florida’s Third District Court of Appeal in implementing the Daubert test as its gatekeeping function stated: “‘a key question to be answered’ in any Daubert inquiry is whether the proposed testimony qualifies as ‘scientific knowledge’ as it is understood and applied in the field of science to aid the trier of fact with information that actually can be or has been tested within the scientific method.” Perez, 138 So.3d at 498.



The third factor focuses on whether the expert testimony will assist the jury (trier of fact) in understanding an issue in the case. Thus, the expert testimony needs to be beyond the understanding of an average lay person and must not potentially confuse or mislead the jury. See U.S. v. Frazier, 387 F.3d 1244, 1262-63 (11th Cir. 2004). Also, the expert testimony must be more than what lawyers can argue in their closing arguments. Id. at 1263.


Please contact David Adelstein at dadelstein@gmail.com or (954) 361-4720 if you have questions or would like more information regarding this article. You can follow David Adelstein on Twitter @DavidAdelstein1.

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