N.H. Rev. Stat. Ann. § 611-B:4

The chief medical examiner may designate in writing an acting chief medical examiner who shall be a licensed physician, certified by the American Board of Pathology as a qualified pathologist with training and experience in forensic medicine. The acting chief medical examiner shall act as the chief medical examiner whenever the chief medical examiner, deputy chief medical examiner, and the associate medical examiner are absent, or unable to act for any cause.