The short answer
What Illinois families should know.
Illinois Rule of Evidence 602 requires a sufficient basis to find that a witness personally knows the matter described. Family members and friends may care deeply about the dispute but still lack firsthand knowledge of a particular event. Sympathy and confidence do not replace an opportunity to observe.
Explain how the witness knows
A witness may have seen an exchange, heard a conversation, handled a transaction, or created a record. Questions establishing that connection help the judge evaluate the testimony. Dates, location, proximity, and the circumstances of observation can matter. A statement beginning with everyone knows may conceal that the witness learned the information from someone else rather than from direct experience.
Separate observation from inference
Seeing a person leave a building does not necessarily establish what occurred inside. Seeing a bank transfer does not automatically establish its purpose. A witness can describe the observable facts and identify any limits on what those facts show. Counsel can then determine whether additional records or testimony are needed. This avoids asking the witness to supply a conclusion beyond their knowledge.
Hearsay is a separate question
A witness may personally remember hearing someone say something, but the statement’s use can still raise hearsay issues. Personal knowledge of the conversation does not automatically establish the truth of what another speaker claimed. The purpose for offering the statement and any applicable exclusion or exception must be evaluated separately. Both foundations may matter in the same short piece of testimony.
Experts operate under additional rules
Rule 602 expressly recognizes the rules concerning an expert’s basis for an opinion. A properly qualified expert may rely on information in a manner different from an ordinary fact witness. That does not permit a lay witness to give specialized conclusions simply because they read documents. Identify the kind of testimony needed and select a witness with the appropriate firsthand knowledge or expertise.
Prepare
Useful next steps
- List exactly what each proposed witness saw, heard, or did.
- Identify records that can fill gaps in a witness’s knowledge.
- Tell counsel which information came from another person.
Avoid
Common missteps
- Treating familiarity with the family as knowledge of every disputed event.
- Asking a witness to turn an assumption into a confident factual statement.
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This article provides general information and is not legal advice. Laws, court rules, local procedures, and individual facts can change the analysis. Reading it or contacting the firm does not create an attorney-client relationship.