N.H. Rev. Stat. Ann. § 651:5-a

Notwithstanding any provision of RSA 651:5 to the contrary, any person convicted of a criminal offense which occurred between May 14, 2014 and July 1, 2015, and while the person was 17 years of age, shall be entitled to an annulment of such conviction upon application to the court. This section shall not apply to any offenses which may continue to be prosecuted as an adult criminal offense after July 1, 2015 against persons who have not yet reached 18 years of age. Annulment requests brought under this section shall not be subject to any filing fee, and may only be brought following the expiration of any sentence imposed by the court. The only permitted basis for denial of an annulment request brought under this section is a written finding by the court, based on clear and convincing evidence, that the subject offense would have qualified for transfer to the superior court pursuant to RSA 169-B:24 and that the prosecution would have pursued such transfer.