SECTION 1. Section 39 of chapter 127 of the General Laws, as appearing in the 2012 Official Edition, is hereby amended by striking out the first paragraph and inserting in place thereof the following 2 paragraphs:-

At the request of the superintendent of any correctional institution of the commonwealth, the commissioner may authorize the transfer, for such period as he may determine, to a segregated unit within any correctional institution of the commonwealth, of any inmate over 21 years of age whose continued retention in the general institution population is detrimental to the program of the institution.

At the request of the superintendent of any correctional institution of the commonwealth, the commissioner may authorize the transfer, for no longer than 48 hours, to a segregated unit within any correctional institution of the commonwealth, of any inmate 21 years of age or younger who poses an immediate and substantial threat to the safety of other inmates or officers. If after 48 hours, in the opinion of the superintendent, conclusive evidence exists, as documented in a written report, that the inmate continues to pose an immediate and substantial threat to other inmates or officers, the inmate may remain in the segregated unit up to an additional 24 hours. The written report shall include reasons why the superintendent believes the inmate continues to pose an immediate and substantial threat to the safety of other inmates or officers.

SECTION 2. Section 40 of said chapter 127, as so appearing, is hereby amended by striking out the first paragraph and inserting in place thereof the following 2 paragraphs:-

For the enforcement of discipline, an inmate over 21 years of age in any correctional institution of the commonwealth may, at the discretion of its superintendent, be confined, for a period not to exceed 15 days for any one offense, to an isolation unit.

Any inmate, 21 years old or younger in any correctional institution, who poses an immediate and substantial threat to the safety of other inmates or officers, may, at the discretion of the superintendent, be confined to an isolation unit for a period not to exceed 48 hours.

SECTION 3. Section 41 of said chapter 127, as so appearing, is hereby amended by striking out the first paragraph and inserting in place thereof the following 2 paragraphs:-

The superintendent or keeper of a jail or house of correction may set aside in such jail or house of correction 1 or more cells to be used as isolation units and for the enforcement of discipline may confine any inmate over 21 years of age thereto; but no prisoner shall be confined to such isolation unit for more than 3 days without informing the sheriff or the county commissioners thereof and of the reasons therefor; and in no case for more than 10 days for any one offense.

Any inmate, 21 years old or younger in any jail or house or correction, who poses an immediate and substantial threat to the safety of other inmates or officers, may, at the discretion of the superintendent or administrator, be confined to an isolation unit for a period not to exceed 48 hours.