What is the purpose of a subpoena in legal proceedings?

A subpoena serves a crucial function in legal proceedings by compelling an individual to appear in court or to produce specified documents that are relevant to a case. This legal instrument is vital for ensuring that all necessary evidence and testimonies are presented during a trial, thereby supporting the judicial process.

When a subpoena is issued, it creates a legal obligation for the recipient to comply. Failure to respond can result in penalties or other legal repercussions. This tool helps maintain the integrity of the trial by ensuring that relevant parties, witnesses, or experts contribute to the case, thereby allowing the judge or jury to fully consider all available information before making a decision.

In contrast, the other options address different aspects of legal proceedings but do not pertain directly to the purpose of a subpoena. For example, changing a venue involves logistical considerations based on fair trial rights and is not directly related to evidence gathering. Dismissing a case due to lack of evidence pertains to the trial's outcome rather than the mechanisms for gathering that evidence. Notifying parties about court sessions relates to procedural communication rather than compelling participation or evidence.