Expert Witnesses in Hawaii
In Hawaii, an expert witness is anyone with reliable, specialized knowledge—derived from education or real-world experience—whose testimony helps the fact-finder and meets reliability standards under HRE Rule 702.
Rules Governing Disclosure
Haw. R. Civ. P. 26 governs discovery related to expert witnesses in Hawaii civil cases. For experts a party expects to call at trial, Rule 26 allows discovery of:
The expert’s identity
The subject matter on which the expert is expected to testify
The substance of the facts and opinions the expert will offer
A summary of the grounds for each opinion
In Hawaii, expert disclosure follows a summary-based framework rather than a formal expert report regime, requiring parties to provide sufficient information to give fair notice of an expert’s expected testimony without exhaustive detail. Expert opinions are typically developed and clarified through written discovery and depositions, rather than through comprehensive pretrial reports. Throughout this process, trial courts exercise broad discretion to supervise the timing, scope, and adequacy of expert disclosures and to prevent unfair surprise.
Disclosures must be made in accordance with deadlines set by the court’s pretrial scheduling order, and failure to comply may result in exclusion under Rule 37 if the non-disclosure is found to be unjustified or prejudicial.
Required Declarations
Although Hawaii does not generally require expert declarations or affidavits as part of standard expert disclosures, such materials commonly become necessary at the dispositive-motion stage, particularly in the context of summary judgment under Haw. R. Civ. P. 56(e). To be effective, an expert affidavit or declaration must be grounded in the expert’s personal knowledge, set forth facts that would be admissible at trial, and establish the expert’s qualifications to address the matters at issue. In medical malpractice actions, expert declarations are frequently essential to defeat summary judgment and must adequately demonstrate both a deviation from the applicable standard of care and proximate causation, supported by competent scientific or clinical evidence.
Admissibility Standards
In Hawaii, an expert witness is defined primarily by Hawaii Rules of Evidence Rule 702, which follows a reliability-focused standard similar to Daubert.
Courts may consider:
Whether the theory or technique can be tested
Peer review and publication
Known or potential error rates
General acceptance in the relevant field
These factors are flexible, not mandatory checklists. Trial courts serve a gatekeeping role to ensure that expert opinions are both relevant and grounded in reliable methodology.
Attorney–Expert Communication Protection
In Hawaii, communications between attorneys and their experts are not subject to automatic disclosure and are evaluated with a careful eye toward protecting the integrity of trial preparation. Courts afford strong protection to exchanges that reflect counsel’s strategy, legal theories, or mental impressions, recognizing these as core work product. At the same time, where an expert relies on factual information or assumptions supplied by counsel in forming an opinion, those inputs may fall within the scope of permissible discovery. Ultimately, trial courts retain wide latitude to draw the line between protected advocacy and discoverable expert foundations, applying a case-specific and practical judgment rather than a rigid rule.
Key Deadlines & Strategy Notes
Expert disclosure deadlines are typically set by pretrial orders or Rule 16 scheduling orders, which vary by court and case complexity. A typical structure includes:
Initial expert disclosure: 90–120 days before trial
Opposing party’s disclosure: 30–60 days after initial disclosure
Rebuttal expert deadline: Often 30 days after the defense disclosure
Daubert or exclusion motions: Filed in advance of the final pretrial conference
From a practical standpoint, counsel are best served by engaging experts early, confirming their availability for both deposition and trial, and anchoring all opinions in peer-reviewed research, testing, or other reliable methods. Because Hawaii courts regularly scrutinize expert testimony for methodological soundness, admissibility preparation should be treated as a core part of case strategy.
Compensation
In Hawaii, expert witnesses are typically compensated pursuant to private retention agreements with the hiring party, covering time spent on review, analysis, preparation, and testimony, with rates varying by discipline and experience. Fee arrangements may not be contingent on the outcome of the case. When an opposing party seeks discovery from a testifying expert, the court may require that party to pay the expert a reasonable fee for time spent responding, most commonly for deposition testimony, as authorized under Rule 26(b)(4) of the Hawaii Rules of Civil Procedure. Trial courts retain broad discretion to resolve fee disputes and to ensure that expert compensation is fair and not used to obstruct discovery.
State-Specific Statutes & Local Rules
Haw. R. Civ. P. 26(b)(4): Expert discovery and disclosure rules
Haw. R. Civ. P. 37: Sanctions for failure to disclose
Haw. R. Civ. P. 56(e): Affidavit requirements for summary judgment
Haw. R. Evid. 702: Codifies the Daubert admissibility standard
