Can a lay witness and an expert witness give testimony that includes opinions or inferences based on case facts?

A lay witness is someone who testifies about facts they have directly observed or experienced, and their testimony is typically limited to these factual observations without the inclusion of opinions or inferences. In contrast, expert witnesses are individuals with specialized knowledge or experience in a particular field, which allows them to offer opinions and inferences that are grounded in their expertise.

The cornerstone of the distinction is that lay witnesses must stick to the facts as they know them, while expert witnesses can draw conclusions based on their training, education, and experience. This delineation helps ensure that the testimony presented in court maintains a level of credibility and reliability, as expert witnesses undergo a more rigorous vetting process to establish their qualifications and the relevance of their opinions to the case at hand.

Therefore, the assertion that a lay witness can provide testimony that includes opinions or inferences based on case facts is not accurate. This clarity is pivotal in maintaining the integrity of the judicial process and ensuring that testimonies are appropriate for the capacity in which the witnesses are presenting them.