Posted on September 11, 2021

How To Qualify An Expert Witness During An Illinois Divorce Hearing Or Trial

During a divorce there may be a need for an expert to testify as to the value of a marital asset or the psychological make-up of a parent and child. The expert is not allowed to just walk into court and start giving their opinion. The expert must be qualified first for their expert opinion to be considered by the judge.

To present evidence in an Illinois court to be weighed by a judge, that evidence must be reliable. Something someone experienced first-hand is more reliable than something they merely heard about second-hand (hearsay).

In an Illinois court room all testimony can be divided into three categories: 1) that which was personally perceived, 2) hearsay and 3) opinion.

The distinctions between different kinds of evidence under the Illinois Rules of Evidence help ensure that courts are only weighing good evidence and are not drowning in nonsense.

“[A party] does not have an unfettered right to offer testimony that is incompetent, privileged, or otherwise inadmissible under standard rules of evidence.”Taylor v. Illinois, 484 US 400 – Supreme Court 1988

What was personally perceived can be admitted into evidence without objection.

Hearsay cannot be admitted because it’s not reliable unless one of the hearsay exceptions has made the evidence sufficiently reliable to be admitted.

Opinion is the collection of personally perceived and hearsay evidence which is then filtered through common sense and/or expertise which allows the witness to state a conclusion.

An opinion might be as simple as “it was 75 degrees that day” or as complicated as “I believe the combination of chemicals in the ground water gave the victim cancer.”

“[T]he general rule is that testimony of a witness’ opinion is not admissible into evidence” People v. Brown, 558 NE 2d 309 – Ill: Appellate Court, 1st Dist. 1990

In order to get an opinion into evidence a party must first qualify the witness testifying to the opinion as a lay opinion witness or an expert witness. Until that witness is qualified as either…they cannot give an opinion.

Well in advance of any witness providing an opinion, those opinion witnesses must be disclosed…but only if that disclosure is asked for.

“Upon written interrogatory, a party must furnish the identities and addresses of witnesses who will testify at trial” Rule 213 – Written Interrogatories to Parties, Ill. Sup. Ct. R. 213

“Supreme Court Rule 213(i) imposes on each party a continuing duty to inform the opponent of new or additional information whenever such information becomes known to the party.” Sullivan v. Edward Hosp., 806 NE 2d 645 – Ill: Supreme Court 2004

“A party has a duty to seasonably supplement or amend any prior answer or response whenever new or additional information subsequently becomes known to that party.” Ill. Sup. Ct. R. 213(i)

Lay Opinion Witnesses During An Illinois Divorce Hearing Or Trial?

Sometimes a witness cannot express something exactly as they observed it. The moment has to be filtered through their opinion to be communicated. For example, you can say that “it was cloudy, the leaves were changing color and you could begin to see your own breath” or you could just say “it was a brisk Autumn day.”

“Lay witness opinion testimony is admissible where the facts could not otherwise be adequately presented or described to the fact finder in such a way as to enable the fact finder to form an opinion or reach an intelligent conclusion. Lay witnesses may relate their opinions or conclusions on what they observed because it is sometimes difficult to describe a person’s mental or physical condition, character or reputation, or the emotions manifest by his or her acts; or things that occur and can be observed, including speed, appearance, odor, flavor, and temperature.” People v. Novak, 643 NE 2d 762 – Ill: Supreme Court 1994

These types of soft, common sense opinions are allowed…but they still must be qualified as opinions in an Illinois court.

Qualifying a lay opinion witness is very simple. You simply must show that their conclusion was logically based on their perception and NOT based on specialized knowledge. In reality, your opposing counsel will let you know via objection if the lay opinion witness does not meet these requirements

“If the witness is not testifying as an expert, the witness’ testimony in the form of opinions or inferences is limited to those opinions or inferences which are (a) rationally based on the perception of the witness, and (b) helpful to a clear understanding of the witness’ testimony or the determination of a fact in issue, and (c) not based on scientific, technical, or other specialized knowledge within the scope of Rule 702.” Ill. R. Evid. 701

Expert Opinion Witnesses In An Illinois Divorce Hearing Or Trial

If an opinion is based on “scientific, technical, or other specialized knowledge” the witness cannot offer their opinion into evidence until they have been qualified as an expert.

“An individual becomes an expert by studying and absorbing a body of knowledge.” Darling v. Charleston Hospital, 211 NE 2d 253 – Ill: Supreme Court 1965

“A witness may thus testify as an expert if he or she has knowledge and experience beyond the average citizen that would assist the jury in evaluating the evidence. There is no particular way in which that expertise had to be acquired; it could have come through formal study, training, or research, or through practical experience, in the relevant specialized field.” People v. Loggins, 130 NE 3d 432 – Ill: Appellate Court, 1st Dist., 3rd Div. 2019 (Citations Omitted)

“Rule 702…sets forth the foundational requirements for expert opinion testimony.” People v. Loggins, 130 NE 3d 432 – Ill: Appellate Court, 1st Dist., 3rd Div. 2019

“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 thereto in the form of an opinion or otherwise. Where an expert witness testifies to an opinion based on a new or novel scientific methodology or principle, the proponent of the opinion has the burden of showing the methodology or scientific principle on which the opinion is based is sufficiently established to have gained general acceptance in the particular field in which it belongs.” Ill. R. Evid. 702

By requiring that a witness be “qualified…by knowledge, skill, experience, training, or education” to offer proposed expert testimony Rule 702 aims to assure both fairness and reliability in the [judicial determinations].” People v. Hillis, 65 NE 3d 357 – Ill: Appellate Court, 4th Dist. 2016

Establishing that your expert witness is sufficiently qualified to testify under Rule 702’s requirements requires that you lay a foundation for their level of expertise.

“An individual will be permitted to testify as an expert if that person’s experience and qualifications afford him or her knowledge that is not common to laypersons, and where such testimony will aid the fact finder in reaching its conclusion. The indicia of expertise is not an assigned level of academic qualifications. Rather, the test is whether the expert has knowledge and experience beyond the average citizen that would assist the jury in evaluating the evidence. The expert may gain his or her knowledge through practical experience rather than scientific study, training, or research. There is no precise requirement as to how the expert acquires skill or experience. Regardless of how specialized knowledge is acquired, whether through education, training, experience, or a combination of each, if the witness possesses such knowledge, he or she may testify as an expert. The burden of establishing the qualifications of an expert witness is on the proponent of the expert’s testimony. The determination of whether a witness qualifies as an expert is within the sound discretion of the trial court.” People v. Novak, 643 NE 2d 762 – Ill: Supreme Court 1994

Example questions to help qualify an expert witness are as follows:

  1. Where did you attend school?
  2. What degrees do you possess?
  3. Are you a member of any professional associations?
  4. Did you specialize in any particular field?
  5. Have you received any honors or awards in your field?
  6. What specific training do you have in the area of your specialty?
  7. Do you have any publications or research?
  8. What licenses do you possess?
  9. How long have you had those licenses?
  10. Do you have any board certifications?
  11. If so, how long have you had those certifications?
  12. Where do you work?
  13. What is your title there?
  14. How long have you been at that job?
  15. What are some of your duties at that place of employment?
  16. Please list your previous places of employment, including each position.
  17. Please state the duties you had at each of your previous positions.
  18. What type of scientific or technical studies have you conducted?
  19. Has your work been peer-reviewed?
  20. Did you prepare a report in this case?
  21. Can you please explain the materials that you reviewed in creating your report?
  22. After you completed your report did you arrive at a conclusion?
  23. Outline the specific facts and data that you relied on in coming to your conclusion.
  24. Describe the scientific or technical principles or methods that you used in coming to your conclusion.
  25. Are those specific scientific or technical principles or methods widely used in your field?
  26. Explain how you relied on those principles or methods
  27. Do you believe that your testimony will be helpful in assisting the judge or jury understand the facts of this case?
  28. Your honor, at this time I tender this witness as an expert in the field of _________.

After qualification, you may begin asking the expert witness questions which call for conclusions.

How To Cross-Examine An Expert Witness During An Illinois Divorce Hearing Or Trial

Just because an expert witness has been properly qualified does not mean that everything the expert says should be taken as the gospel truth.

It will be the duty of the opposing counsel to find any errors or biases in the expert witness’s testimony.

“[O]n cross-examination, counsel may probe an expert witness’s qualifications, experience and sincerity, the weaknesses in the basis of his opinions, the sufficiency of his assumptions, and the general soundness of his opinion. An expert may also be cross-examined on material he reviews, but from which he did not ultimately rely.” Wardwell v. UNION PACIFIC RAILROAD COMPANY, Ill: Appellate Court, 5th Dist. 2016

The expert’s opinion still must comply with the Illinois Rules of Evidence to ensure the reliability of the expert’s opinion.

The content of the expert’s opinion has to be based on what they observed personally or based on accepted inferences within their field.

“The facts or data in the particular case upon which an expert bases an opinion or inference may be those perceived by or made known to the expert at or before the hearing. If of a type reasonably relied upon by experts in the particular field in forming opinions or inferences upon the subject, the facts or data need not be admissible in evidence.” Ill. R. Evid. 703

“[A]n expert can give his opinion based upon facts that are not in evidence if those facts are of a type reasonably relied upon by experts in the particular field.” People v. Pasch, 604 NE 2d 294 – Ill: Supreme Court 1992

The expert is permitted to use the work of other experts in forming their opinion.

“It is not error to permit an expert to testify regarding reports or…tests performed by other [experts in the same field] and which he examined in reaching his own opinion.” McCray v. SALAH UDDIN SHAMS, MD, SC, 587 NE 2d 66 – Ill: Appellate Court, 2nd Dist. 1992

While the expert witness must base his or her conclusions on valid facts, the expert witness is not required to start their testimony with all of the facts. Those facts only need come to issue if the cross-examination so requires.

“The expert may testify in terms of opinion or inference and give reasons therefor without first testifying to the underlying facts or data, unless the court requires otherwise. The expert may in any event be required to disclose the underlying facts or data on cross-examination.” Rule 705 – Disclosure of Facts or Data Underlying Expert Opinion, Ill. R. Evid. 705

If an expert is not using information that other experts would use in order to arrive at their conclusion…that is not a valid expert opinion.

Establishing that the information the expert used is not typically used by other experts obviously requires the testimony…of another expert.

The facts an expert bases his opinion on are not automatically admitted into evidence, however. Just the opinion is admitted into evidence. Most of those facts will be hearsay.

“Rule 703 did not create an exception to the hearsay rule; the underlying facts or data upon which an expert in a particular field is found to have reasonably relied are not admitted for their truth. The underlying facts or data are admitted for the limited purpose of explaining the basis for the expert witness’ opinion.” City of Chicago v. Anthony, 554 NE 2d 1381 – Ill: Supreme Court 1990 (Quotations Omitted)

Furthermore, not only the facts the expert relies on will be in question. So, will the expert’s methods. If an expert is relying on a new theory like “Parental Alienation Syndrome” (This term was invented in 1985 and has since largely been abandoned).

New and novel evidence is not permitted as the basis of an opinion in an Illinois courtroom.

“In Illinois, the admission of scientific evidence is governed by the Frye standard which has now been codified by the Illinois Rules of Evidence… The purpose of the Frye test is to exclude new or novel scientific evidence that undeservedly creates a perception of certainty when the basis for the evidence or opinion is actually invalid.” In re Detention of New, 21 NE 3d 406 – Ill: Supreme Court 2014

An expert’s testimony can also be counteracted by the admission of literature which is standard in the field. This literature can be admitted into evidence via judicial notice.

“To prevent cross-examination upon the relevant body of knowledge serves only to protect the ignorant or unscrupulous expert witness. In our opinion expert testimony will be a more effective tool in the attainment of justice if cross-examination is permitted as to the views of recognized authorities, expressed in treatises or periodicals written for professional colleagues. The author’s competence is established if the judge takes judicial notice of it, or if it is established by a witness expert in the subject.” Darling v. Charleston Hospital, 211 NE 2d 253 – Ill: Supreme Court 1965

The Scope Of An Expert Witness’s Testimony In An Illinois Divorce Hearing or Trial

An expert witness should be seen as a witness plus. They can testify like any other witness AND provide expert testimony.

“[A] witness can offer both lay and expert testimony in the same case.” People v. Mariani, Ill: Appellate Court, 4th Dist. 2021

“[A] witness can qualify as both a lay fact witness and an expert witness—or more precisely, can offer both lay and expert testimony—in the same case. And an expert may base an opinion (as a lay witness must) on facts that the expert has personally observed.” People v. Loggins, 130 NE 3d 432 – Ill: Appellate Court, 1st Dist., 3rd Div. 2019

Expert Testimony That Calls For A Legal Conclusion In An Illinois Divorce Hearing Or Trial

Questions to a witness are supposed to elicit facts they have personally observed. “Accordingly, requests for legal conclusions are improper” P.R.S. International, Inc. v. Shred Pax Corp., 184 Ill. 2d 224, 236 (Ill. 1998)

However, if the witness has been certified as an expert, they may answer questions that call for a legal conclusion such as “who would be the better primary parent?”

“Testimony in the form of an opinion or inference otherwise admissible is not objectionable because it embraces an ultimate issue to be decided by the trier of fact.” Ill. R. Evid. 704

Of course, if you can prove the expert witness is not applying their expertise and is just guessing then “expert opinions based upon the witness’s guess, speculation, or conjecture as to what he believed might have happened are inadmissible.” Modelski v. Navistar Intern. Transp. Corp., 707 NE 2d 239 – Ill: Appellate Court, 1st Dist., 4th Div. 1999

If you need an expert to testify during your Illinois divorce, you are going to need to know how get your expert qualified. Likewise, if your spouse discloses an expert witness, you can keep that expert’s testimony out of court if you know how. Contact my Chicago, Illinois family law firm to speak with an experienced Illinois divorce attorney.

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Russell Knight

Russell D. Knight has been practicing family law as a Chicago divorce lawyer since 2006. Russell D. Knight amicably resolves tough cases while remaining a strong advocate for his client’s interests.

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