Expert Witness Disclosure: A Practitioner Overview
Pre-trial expert disclosure typically requires a written statement of the expert's identity, opinions, the bases for those opinions, qualifications, prior testimony, and compensation. Content and timing requirements vary by jurisdiction. Missing a disclosure requirement is a common basis for expert exclusion. Attorneys are responsible for confirming the governing framework against primary sources.
What is pre-trial expert disclosure?
Pre-trial expert disclosure is the formal statement to the opposing party of the expert's expected testimony before trial. Depending on the jurisdiction, the disclosure may take the form of a written report, an interrogatory-style answer signed by the expert, or another format set by the governing framework. The point is to identify the expert, describe what the expert will say, and provide the basis for the opinions in time for the opposing party to prepare a response.
Common content elements
Most disclosure frameworks call for the expert's identity, the subject matter, the substance of opinions, the bases for those opinions, qualifications, and (in many jurisdictions) prior testimony and compensation. The exact inventory varies by jurisdiction, and trial-track engagements in federal court typically call for a more comprehensive written report than settlement-stage state-court disclosure.
Timing
Disclosure timing is set by the case scheduling order or by the governing framework's default deadlines. Practitioners should pull the scheduling order at the outset of the case and calendar both the disclosure deadline and the close of expert discovery.
Supplementation
Most frameworks impose a continuing duty to supplement when the disclosing party learns the prior response is incomplete or incorrect. Failure to supplement can support a motion to preclude the expert testimony at trial.
Verify the governing framework
This page provides a general overview only and does not provide legal advice. Disclosure rules vary by jurisdiction and change over time. Always confirm the governing framework, the court's scheduling order, and any local rule requirements against primary sources for the specific case.
Frequently Asked Questions
Does every retained expert need to produce a written report?
It depends on the jurisdiction. Federal-court trial-track engagements typically require a comprehensive written report; many state frameworks accept a substance-of-opinions statement instead, sometimes via interrogatory. Confirm the governing framework for the specific case.
What counts as 'facts or data considered'?
All materials the expert reviewed in forming the opinion, including those the expert chose not to rely upon. Most jurisdictions interpret this category broadly.
Related
References
- Duty to Disclose; General Provisions Governing Discovery, Federal Rules of Civil Procedure. law.cornell.eduCase Law
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