N.H. Rev. Stat. Ann. § 592-A:12

Any person who attends any court for the state in criminal cases pursuant to subpoena shall sign a witness log, which shall be available in the office of the clerk of court, on which the individual shall provide the following information: name, mailing address, and the name of the case for which the person was subpoenaed. The prosecuting agency shall review the log each day and certify that each individual appeared as indicated on the log.