Mass. Gen. Laws ch. 265, § 4: Accessory in duel

Section 4. An inhabitant or resident of this commonwealth who, by previous appointment or engagement made within the same, becomes the second of either party in such duel and is present as a second when a mortal wound is inflicted upon a person whereof he dies within this commonwealth shall be an accessory before the fact to murder in this commonwealth, and may be indicted, tried and convicted in the county where the death occurs.