§ 90.704, Fla. Stat. — Basis of Opinion Testimony by Experts
Plain English
This rule answers a practical question: what can an expert rely on to form an opinion? The answer is broad — facts or data the expert perceived or were made known to them, before or during trial. And here’s the key: if the facts or data are of a type experts in the field reasonably rely on, they don’t themselves have to be admissible in evidence. A doctor can rely on another physician’s report; an accident reconstructionist on data they didn’t personally collect. But there’s a guardrail added with the move to Daubert: otherwise-inadmissible facts or data may not be disclosed to the jury by the opinion’s proponent unless the court finds their value in helping the jury evaluate the opinion substantially outweighs their prejudicial effect.
From the Courtroom
The classic maneuver is trying to use an expert as a conduit to slip inadmissible hearsay to the jury — “my opinion is based on what these three witnesses told me.” 90.704 lets the expert rely on it, but the last sentence stops the proponent from broadcasting that inadmissible material to the jury unless the court runs the balancing test first.
Key Points & Authority
- § 90.704, Fla. Stat. — An expert may base an opinion on facts or data of a type reasonably relied upon by experts in the field, even if those facts/data are not themselves admissible.
- Disclosure guardrail: otherwise-inadmissible bases may not be disclosed to the jury by the proponent unless their probative value in evaluating the opinion substantially outweighs prejudice.
- Federal parallel: Fed. R. Evid. 703 (numbering offset — Florida’s 90.704 maps to federal 703).
Federal Parallel
The federal counterpart is Fed. R. Evid. 703 (numbering offset — Florida’s § 90.704 corresponds to federal Rule 703). Both let experts rely on inadmissible facts of a type reasonably relied upon, with a balancing test before such material is disclosed to the jury.
About this rule walkthrough
Part of The Evidence Code, hosted by John M. Phillips — Board Certified Civil Trial Lawyer, Court TV analyst, admitted in 8 states + 9 federal districts + SCOTUS.
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Educational only — not legal advice.
Rule Text (verbatim from the Florida Supreme Court)
The facts or data upon which an expert bases an opinion or inference may be those perceived by, or made known to, the expert at or before the trial. If the facts or data are of a type reasonably relied upon by experts in the subject to support the opinion expressed, the facts or data need not be admissible in evidence. Facts or data that are otherwise inadmissible may not be disclosed to the jury by the proponent of the opinion or inference unless the court determines that their probative value in assisting the jury to evaluate the expert’s opinion substantially outweighs their prejudicial effect.
Educational reference. Educational only — not legal advice.
What this rule means in plain English
Section 90.704 lets an expert base an opinion on facts or data reasonably relied upon by experts in the field even if inadmissible, but bars the proponent from disclosing otherwise-inadmissible bases to the jury unless their probative value substantially outweighs prejudice.