An Illinois Criminal Subpoena is a legal document issued by a prosecuting attorney or court in the state of Illinois. It requires a witness to appear in court or provide evidence in a criminal case. There are two types of Illinois Criminal Subpoenas: a Subpoena Ducks Cecum, which orders a witness to appear and bring certain documents or other materials, and a Subpoena Ad Testificandum, which orders a witness to appear and give testimony. Both types of subpoenas must be served on the witness in accordance with Illinois law. Failure to comply with a criminal subpoena can result in criminal penalties.