RSA 461-A:11 Modification of Parental Rights and Responsibilities.

I. The court may issue an order modifying a permanent order concerning parental rights and responsibilities under any of the following circumstances:
(a) The parties agree to a modification.
(b) If the court finds repeated, intentional, and unwarranted interference by a parent with the residential responsibilities of the other parent, the court may order a change in the parental rights and responsibilities without the necessity of showing harm to the child, if the court determines that such change would be in accordance with the best interests of the child.
(c) If the court finds by clear and convincing evidence that the child's present environment is detrimental to the child's physical, mental, or emotional health, and the advantage to the child of modifying the o