Mass. Gen. Laws ch. 209B, § 9: Testimony of witnesses outside state

Section 9. In addition to other procedural devices available to a party, any party to the proceeding or a guardian ad litem or other representative of the child may adduce testimony of witnesses, including parties and the child, by deposition or otherwise, in another state. The court on its own motion may direct that the testimony of a person be taken in another state and may prescribe the manner in which and the terms upon which the testimony shall be taken.