Which instrument is used to compel a witness to appear and to perform an act?

• A. Subpoena
• B. Summons
• C. Interrogatories
• D. Deposition

Answer: (A)

A subpoena is the instrument used to compel a witness to appear and to perform an act. It is a legal order that can require a person to testify in court (subpoena ad testificandum) or to produce documents and other evidence (subpoena duces tecum), or to carry out another specified action. Because it carries legal force, noncompliance can lead to penalties such as contempt of court. This makes the subpoena the go-to tool for forcing attendance and ensuring witnesses or records are available for a case. By contrast, a summons mainly serves to notify someone of a lawsuit and require their appearance, but it doesn’t routinely compel the production of documents or other acts. Interrogatories are written questions for discovery, not tools to compel appearance, and a deposition is a testimony session that typically occurs after a subpoena or court order has been issued.