N.H. Rev. Stat. § 159-E:2
In light of the long-standing practice of cooperation between federal, state, and local law enforcement agencies, nothing in this chapter shall prevent a state, county, or local official from cooperating with or rendering aid or assistance to federal officials in any circumstance where there is reasonable suspicion to believe that a person who is the subject of an investigation for violation of federal firearms law covered by RSA 159-E:1 also has committed, is committing, or is about to commit a violation of New Hampshire law or a violation of a federal law, regulation, order, or practice not covered by RSA 159-E:1. Nothing in this chapter shall prevent a state, county, or local official from providing authorized federal officials, upon their request, with official state, county, or local records that are available to the public or which constitute criminal history records maintained by an agency of state, county, or local government, or taking any other action necessary to fulfill or comply with the state's obligations under the National Crime Prevention and Privacy Compact approved and ratified in RSA 106-B:14, III, provided that the provisions of this chapter shall not provide for the distribution of information required to be destroyed pursuant to 18 U.S.C. section 922 (t)(2)(C). Nothing in this chapter shall prohibit the judicial branch from entering protective order information into law enforcement databases.
RSA 159-E:2