Mass. Gen. Laws ch. 234A § 13
On or before the first day of September of each year, the office of the jury commissioner shall randomly select prospective jurors for each city and town from the corresponding numbered resident list or numbered resident file. Each such numbered resident, so identified and selected, shall be a prospective juror of the city or town. The random procedure and method used for the selection of prospective jurors and the method of generation of random numbers shall be specified in the regulations of the jury commissioner. Technical data on the integrity of the random number generation method used under this section shall be compiled by the office of jury commissioner. Such data shall be available to members of the public upon request.
Mass. Gen. Laws ch. 234A, § 13