Which type of witness provides facts and/or opinions about the case?

An expert witness is someone who possesses specialized knowledge or expertise in a particular field relevant to the case. This knowledge can encompass a variety of professional areas such as medical, scientific, financial, or technical disciplines. The primary role of an expert witness is to provide the court with factual information and informed opinions that are beyond the understanding of the average person. These opinions are based on their expertise and are intended to assist the judge or jury in understanding complex issues related to the case.

For example, a medical expert may explain the implications of a specific injury and how it could affect a person's life, while an expert in forensics could analyze evidence and draw conclusions that support or refute claims made in the case. The contributions of an expert witness can significantly influence the outcomes of legal proceedings because they provide clarity and context to specialized knowledge that supports arguments and helps in decision-making.

In contrast, a lay witness typically shares observations based on their personal perceptions without being qualified to provide expert opinions. Character witnesses provide testimony regarding a person's character rather than the specifics of the case. Percipient witnesses are those who perceive an event related to the case and provide firsthand accounts, usually recounting what they saw or heard, rather than offering expert analysis.