Using Expert Witnesses to Strengthen Your Illinois Divorce Case

July 22nd, 2025 by Tiffany Hughes

In Illinois divorces, the court often deals with complex legal, financial, medical, or psychological issues. To assist in resolving these matters, the use of expert witnesses can play a critical role. While judges are certainly not bound by expert opinions, expert testimony can be persuasive and frequently shapes the final decisions in contested cases. Understanding what determines someone as an expert witness, the types of expert witnesses in an Illinois divorce, and how expert witnesses are utilized in a divorce is essential for litigants and practitioners alike.

Types of Expert Witnesses in Illinois Divorce Cases

            Generally speaking, there are two types of expert witnesses in an Illinois divorce: independent expert witnesses and controlled expert witnesses. Independent expert witnesses are expert witnesses that are appointed by the court or a mutually agreed-upon evaluator. On the other hand, controlled expert witnesses are either one of the parties, the party’s employee, or an expert retained and paid for by one of the parties.

Who Can Serve as an Expert Witness in Illinois?

In Illinois, what qualifies someone as an expert witness is defined by statute but is very broad. To qualify, a person must possess knowledge, skill, experience, training, or education that exceeds that of the average person and that could help the judge or jury better understand evidence or determine a fact in issue in the case. This threshold ensures that courts can consider a broad range of specialized input while still requiring a reasonable level of credibility and reliability.

What Can an Expert Witness Testify About? 

The scope of what an expert witness can testify about is also broad. Their opinions must be based on the reasonable reliance standard, meaning the expert’s testimony must be based on materials and methods that professionals in their field would reasonably rely on in forming an opinion. Experts can address nearly any subject relevant to the case, such as asset valuations, business income, parenting arrangements, psychological evaluations, employability, or medical conditions. Their primary role is to provide clarity and support the judge’s fact-finding mission.

When Should an Expert Witness be Used?

Deciding when an expert witness should be used involves evaluating the key issues in dispute. For example, if a spouse’s mental health is raised in the context of parenting time, a mental health expert may be appropriate. If business income or real estate value is contested, then financial or valuation experts may be necessary. An experienced attorney can help assess the matter and determine which experts may strengthen the case.

How Are Expert Witnesses Utilized in a Divorce?

1. Recommendations for Allocation of Parental Responsibilities (Formerly Known as “Child Custody”): Frequently employed during the pendency of any case involving children and the allocation of parental rights and parenting time, child psychologists can meet with the children to assess their emotional, physical, and psychological needs and make recommendations with regard to parenting time schedules that best promote their overall well-being.

2. Mental Health and Medical Condition Concerns: When the mental health of a party is at issue, witness testimony from a psychologist or psychiatrist may be employed to give the judge a more accurate picture of the mental health of the party in question and the implications that it may have for parenting time, allocation of parental responsibilities, future work prospects with regard to maintenance payments, and other important issues that often arise during the dissolution of marriage. Expert testimony from other physicians can also be used in the same way when physical health is at issue.

3. Spousal Support or Maintenance Determinations: Vocational experts assess a party seeking maintenance by asking questions about their work history and experience, qualifications for future employment, and more to make an objective determination about their reasonable employment prospects. The outcome of this evaluation can help the court in determining the amount and duration of maintenance to be awarded, if any.

4. Financial Asset Valuations: Financial advisors can weigh in on topics such as tax implications, division of retirement accounts, division of stock and stock options, and other related matters to ensure that the dissolution of marriage and division of assets is done without significant detriment to the parties’ financial state.

5. Personal and Real Property Valuators: The use a real estate valuator can aid in determining the fair market value of the marital residence or other properties owned by the parties to help determine the equity in a property. Often times, determining the value of the marital residence can guide the division of other assets, so this expert testimony can be especially useful.

6. Business Valuations: A business valuator can be employed to give expert testimony regarding the value of a business and what its future prospects could likely be. Courts find this information very useful when trying to determine maintenance and child support amounts because income from the business in question is to be factored into those amount determinations.

There are numerous benefits of using an expert witness in divorce proceedings. Experts can make complicated issues easier to understand, lend credibility to your claims, and provide the court with reliable evidence to support property division, spousal support, parenting schedules, and more. By using experts strategically, parties may avoid drawn-out litigation or strengthen their position during settlement negotiations.

If you are going through a divorce in Illinois and anticipate disputes over parenting, financial assets, or spousal support, the involvement of qualified expert witnesses can make a substantial difference. By understanding when expert witnesses should be used, what they can testify about, and ensuring their admissibility of expert testimony in court, you can build a stronger, more informed case.

Need More Information or Representation?

If you are thinking of hiring an expert witness, give The Law Office of Tiffany M. Hughes, P.C. a call today at 773-893-0228 for a confidential, complimentary 30-minute phone consultation or email Tiffany Hughes directly at Tiffanyhughes@thugheslaw.com. Our entire practice is solely dedicated to the area of family law. We are highly experienced in representing anyone who is getting a divorce, who is engaged in a child custody battle, who is seeking to include expert testimony in their Illinois divorce trial, who is asking what determines someone as an expert witness and wants to understand how that affects their case, who is questioning the admissibility of expert testimony in court and whether it will support their claims, who wants guidance on how expert witnesses are utilized in a divorce and what role they play in litigation, who is weighing the benefits of using an expert witness to strengthen their position, who needs assistance in identifying the different types of expert witnesses in an Illinois divorce that may apply to their situation, or who wants help gathering information on what an expert witness can testify about and how that testimony may impact the outcome of their Illinois divorce case.

About Tiffany M. Hughes, Divorce Attorney, Principal, Managing Partner, The Law Office of Tiffany M. Hughes, P.C.:

Tiffany M. Hughes is a divorce attorney and Managing Partner of The Law office of Tiffany M. Hughes. Recognized as a Top 100 Lawyer in Lawyers Magazine in 2018 and 2019, Super Lawyer from 2016 to date, and in addition to numerous other accolades, Ms. Hughes represents individuals in all aspects of family and matrimonial law proceedings, including litigation, mediation, allocation of parental responsibility (formerly known as custody), parentage, divorce and other child-related matters.

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This blog is made available by The Law Office of Tiffany M. Hughes, P.C. for educational purposes only as well as to give you general information and a general understanding of Illinois law, not to provide specific legal advice. By using this website you understand that there is no attorney client relationship between you and The Law Office of Tiffany M. Hughes, P.C. The website should not be used as a substitute for competent legal advice from a licensed professional attorney in Illinois.  The law changes constantly and we do not go back in time to edit old posts that may be affected by these changes.  If you have any questions about Illinois law, which is the only State this blog and website discusses, please call The Law Office of Tiffany M. Hughes, P.C. for a complimentary phone consultation and do not draw any legal conclusions without speaking to a competent attorney in Illinois first.