BY Spencer Cresswell
The credibility of an expert witness is often the linchpin of a successful litigation strategy. An expert’s prior testimony can significantly impact their perceived reliability, either bolstering or undermining their credibility. Understanding how past testimony can affect an expert’s current case involvement is crucial for attorneys when selecting and vetting expert witnesses.
Consistency in Opinions: An expert’s past testimony should align with their current opinions. Inconsistencies can lead to perceptions of unreliability or bias. Attorneys must scrutinize previous depositions, trial testimonies, and reports to ensure that the expert’s opinions remain consistent over time. Any significant deviations must be explained convincingly to avoid credibility issues.
Consistency with Methodology: Beyond opinions, the methodologies employed by the expert should exhibit consistency. If an expert has previously used a specific methodology to reach conclusions, a sudden departure without valid justification can raise red flags. Ensuring methodological consistency safeguards against attacks on the expert’s credibility based on perceived opportunism or lack of rigor.
Impeachment by Prior Inconsistent Statements: Opposing counsel can exploit discrepancies between an expert’s past and present testimony to impeach their credibility. Prior inconsistent statements can be highlighted during cross-examination to suggest that the expert’s opinions are unreliable or influenced by external factors, such as financial incentives or pressure from retaining counsel.
Highlighting Bias or Advocacy: If an expert’s past testimony indicates a pattern of bias or advocacy, it can be used to challenge their objectivity. Cross-examiners may focus on the expert’s history to demonstrate a propensity to favor particular parties or outcomes, undermining their impartiality in the current case.
Obtaining Transcripts and Reports: During the discovery phase, attorneys should obtain transcripts and reports of the expert’s prior testimonies. These documents provide insights into the expert’s previous positions and any potential vulnerabilities. A thorough review is essential to anticipate and counter challenges to the expert’s credibility.
Interrogatories and Depositions: Attorneys can use interrogatories and depositions to probe the expert’s past testimony. By questioning the expert about previous cases, attorneys can gauge their ability to defend their past opinions and methodologies. This process also reveals how well the expert can handle cross-examination on their prior statements.
Preemptive Disclosure: If an expert’s prior testimony contains potentially damaging information, preemptive disclosure can mitigate its impact. By addressing inconsistencies or controversial statements upfront, attorneys can control the narrative and provide context, reducing the effectiveness of opposing counsel’s attacks.
Expert Preparation: Preparing the expert to address prior testimony issues is critical. This includes rehearsing responses to likely cross-examination questions and developing explanations for any inconsistencies. Well-prepared experts can confidently articulate their positions, minimizing the damage from prior testimonies.
Evaluating Testimonial History: When selecting expert witnesses, attorneys should evaluate the expert’s testimonial history as part of their due diligence. This includes examining the frequency and nature of the expert’s prior engagements and assessing whether their testimony has been subject to successful challenges or exclusions.
Longevity and Reputation: Experts with long-standing reputations for reliable testimony are often viewed more favorably by courts. Attorneys should consider the expert’s reputation within their field and any accolades or recognition that attest to their credibility and expertise.
An expert witness’s prior testimony can significantly influence their credibility in current litigation. Consistency in opinions and methodologies, along with a robust testimonial history, are essential attributes of a credible expert. Attorneys must diligently vet potential experts, scrutinizing past testimonies and preparing them to address any vulnerabilities. By doing so, they can strengthen the expert’s credibility and enhance their case’s overall persuasive power.
Spencer serves as Vice President of Account Management, where he leads ExpertConnect Litigation Support’s Business Development activities. Spencer especially enjoys helping clients find highly specific and specialized experts in patent litigation matters. Prior to joining ExpertConnect, Spencer worked in international government relations focusing primarily on the defense and homeland security industries.
