During the trial, each party presents witnesses and evidence. The evidence, in both verbal and non-verbal forms, is presented through witnesses who are placed under oath. The attorneys do not testify in a case, they facilitate the presentation of testimony from the witnesses. If necessary to assure the presence of a witness or to compel the production of documents at trial, subpoenas are issued to procure witnesses’ appearances in court along with documentary evidence in their possession. Any person who fails to obey a subpoena may be sanctioned by the court.