In a case involving expert testimony, what is typically expected of an expert witness?

In cases involving expert testimony, an expert witness is expected to rely on established facts and data within their respective field. This means that their opinions and conclusions should be grounded in a solid foundation of scientific evidence, recognized methodologies, and the prevailing knowledge in their discipline. The primary goal of expert testimony is to assist the court in understanding complex subject matter that may be outside the common knowledge of a typical juror. By basing their opinions on established facts and data, experts can provide credible, reliable insights that help the court reach informed decisions.

The emphasis on grounding their testimony in established facts ensures that the expert's opinion is not just subjective or speculative but rather supported by objective evidence and accepted practices. This is crucial in legal settings, where the integrity and clarity of information can significantly impact the outcome of a case. Therefore, an expert witness’s responsibility involves thorough research, preparation, and adherence to the standards of their profession to serve the interests of justice effectively.