Mass. Gen. Laws ch. 194 § 16
If a public administrator neglects to return an inventory, settle an account or perform any other duty incumbent on him in relation to an estate, and there appears to be no heir entitled thereto, the district attorney for the district where the administrator received his letters shall, in behalf of the commonwealth, prosecute all suits and do all acts necessary to insure a prompt and faithful administration of the estate and the payment of the proceeds thereof into the state treasury; and if no heir has, within two years after the granting of letters of administration, appeared and made claim in the probate court for his interest in such estate, it shall be presumed that there is no such heir and the burden of proving his existence shall be upon the public administrator.
Each register of probate shall forthwith notify the proper district attorney and the attorney general of any breach of duty on the part of a public administrator in relation to any estate under his charge, of which such register has knowledge or which the records in his registry disclose.
Mass. Gen. Laws ch. 194, § 16