Wisconsin Expert Witness Discovery Rules

What Is the Scope of Expert Discovery in Wisconsin?

In Wisconsin, expert discovery is governed by specific state statutes that outline the permissible scope and requirements. Under Wis. Stat. § 804.01(2)(d), parties are allowed to discover the identity of expert witnesses expected to testify at trial. This includes the subject matter of their testimony, the substance of the facts and opinions they will offer, and a summary of the grounds for each opinion. Wisconsin’s approach shares similarities with Federal Rule of Civil Procedure 26(b)(4) but operates under its own distinct framework.

The statute delineates the boundaries for discovery, explicitly limiting access to draft reports and certain communications with experts unless they directly relate to the expert's testimony. Consulting expert materials are also generally protected unless exceptional circumstances exist. The state’s regulations emphasize transparency in expert testimony, while simultaneously safeguarding the confidentiality of preparatory communications and preliminary drafts.

Timing and Procedure for Expert Discovery in Wisconsin

Expert discovery in Wisconsin typically takes place after initial disclosures and is structured by court-ordered deadlines. The procedural timeline often requires plaintiffs to submit expert reports by a designated date, with defendants following a few months later. These deadlines are crucial as failure to comply can result in exclusion from the trial.

Key procedural steps include:

• Exchange of Expert Information: Parties must disclose expert identities and provide summaries or reports by the court-ordered deadline.
• Depositions: These are usually conducted after the exchange of reports, allowing parties to question experts under oath.
• Interrogatories and Requests for Production: Parties may use these tools to gather detailed information about the expert’s opinions and the basis for them.

Wis. Stat. § 804.01(5)(b) mandates that parties update their expert disclosures if there are any changes in the expert's opinion, ensuring ongoing transparency up to the trial.

What Methods of Expert Discovery Are Permitted in Wisconsin?

Wisconsin permits several methods for expert discovery, each aimed at ensuring thorough preparation for trial:

• Depositions: Allowed and commonly used to explore the expert’s opinions and the basis for them post-report exchange.
• Interrogatories: Written questions that must be answered in detail regarding the expert's testimony.
• Document Requests: Parties may request documents related to the expert’s analysis and opinions.

The state's rules focus on testifying experts, with consulting experts largely shielded from discovery unless a party can demonstrate a substantial need or exceptional circumstances.

Limits on Discovery of Expert Materials and Communications

Wisconsin law carefully restricts discovery of certain expert materials and communications to maintain the integrity of the preparatory process. Under the existing framework, draft reports and attorney-expert communications are not typically discoverable unless they directly pertain to the expert’s testimony. However, discovery may extend to:

• Compensation Details: Information regarding the expert’s compensation may be subject to discovery to assess potential bias.
• Reliance Materials: Documents or data considered by the expert in forming their opinions are generally discoverable.

Wisconsin follows the Daubert standard for admissibility of expert testimony under Wis. Stat. § 907.02, which can prompt pretrial motions but does not expand discovery beyond the established scope.

Consequences for Noncompliance or Discovery Violations

Noncompliance with expert discovery rules in Wisconsin can result in significant sanctions. Under Wis. Stat. § 804.12(4), a court may exclude the expert’s testimony if a party fails to disclose the expert or provide the required report or summary. Other potential sanctions include:

• Monetary Penalties: Fines imposed on parties for failure to comply with discovery obligations.
• Continuances: Delays in trial proceedings to allow for compliance.
• Exclusion: Preclusion of expert testimony at trial for failing to adhere to procedural requirements.

Relevant Rules and Legal Authority in Wisconsin

The primary statutes governing expert discovery in Wisconsin include:

• [Wis. Stat. § 804.01(2)(d)](https://docs.legis.wisconsin.gov/document/statutes/804.01): Governs the discovery of expert identities and opinions.
• Wis. Stat. § 804.01(5)(b): Addresses the duty to supplement expert disclosures.
• Wis. Stat. § 804.12(4): Provides for sanctions related to noncompliance.
• Wis. Stat. § 907.02: Adopts the Daubert standard for expert testimony admissibility.

These rules provide a comprehensive framework that balances the need for thorough expert discovery with protections for privileged communications and materials.