N.H. Rev. Stat. § 260:16
The department may destroy, at the end of 5 years from the date of filing, originals or copies, including photographs, microphotographs, or photographic film, of reports required by law of accidents and applications for licenses to drive motor vehicles and for the registration thereof. The department may destroy any obsolete number plates and forms which, in the director's opinion, are no longer of any value to the state. The time limit provided herein shall not apply in the case of the destruction of original records, papers, or documents as provided in RSA 260:19. This section shall not be construed as allowing the destruction of any record of conviction maintained for the purposes of RSA 265-A:2, I.
RSA 260:16
1919, 12:1. 1925, 49:1. PL 99 :8. 1929, 55:2. RL 115:8. 1947, 15:2. RSA 259:12. 1981, 146:1; 479:16. 2006, 260:16, eff. Jan. 1, 2007.