Impact of Expert Witness Testimony Credibility

Abstract

Expert witness testimony plays a central role in modern judicial systems by interpreting complex scientific, medical, technological, and psychological evidence. However, the credibility of such testimony can significantly influence juror perception, judicial outcomes, and public trust. This study examines the psychological, procedural, and contextual factors affecting expert credibility, including qualifications, communication style, bias perception, adversarial framing, and methodological rigor. Using a hypothetical cross-national dataset, the paper evaluates how jurors rate expert reliability in the United States, India, and Italy. Findings indicate that credibility is influenced not only by academic expertise but also by perceived neutrality, clarity, and courtroom demeanor. A credibility assessment model is proposed to enhance reliability and reduce wrongful conviction risks.