District of Columbia Subpoena (Updated November 2009) is a legal document issued by a court to compel a person or entity to provide evidence in a court of law. It is typically used to obtain documents, testimony, and other tangible evidence relevant to a legal case. There are two types of District of Columbia Subpoena (Updated November 2009): subpoena ad testificandum and subpoena duces tecum. A subpoena ad testificandum requires a person to appear in court to testify as a witness, while a subpoena duces tecum requires a person or entity to provide documents or other tangible evidence relevant to a case. Both types of subpoenas are legally binding and failure to comply can result in contempt of court.