Mass. Gen. Laws ch. 127 § 20B
The sheriff of any county and, in the case of women who are committed as pretrial detainees to the Massachusetts Correctional Institution at Framingham, the commissioner of correction, subject to rules and regulations established in accordance with this section, may permit a detainee who is committed to a jail awaiting disposition of any criminal matter, except those being held for offenses listed in this section, to be classified to a pretrial diversion program operated by the sheriff's office in the county where the court that committed the detainee is sitting.
The sheriff may extend the limits of the place of confinement of a detainee for the purpose of participation in this program; provided, however, that such place of confinement shall not include alcohol and drug free housing unless such housing is certified pursuant to section 18A of chapter 17; and provided further, that the sheriff shall establish a classification system to determine the suitability of detainees who may be potential participants in this program. A person permitted to be away from the jail due to participation in this program may be accompanied by an employee of the sheriff's office in the discretion of the sheriff or his designee.
For the duration of his participation in the program, the detainee shall be deemed to be in custody as a pretrial detainee for the purpose of receiving credit pursuant to section 129B of chapter 127 and section 33A of chapter 279 toward any sentence he may receive, and may be charged with escape pursuant to section 16 of chapter 268 should he leave the place to which he is classified pursuant to his participation in the program without authorization or should he escape from custody while he is being transported pursuant to his participation in the program. Additionally for the duration of his participation in this program only, the detainee may receive additional deductions from any sentence that may be imposed for the offense for which he was detained, for participation in work, education or treatment programs designated by the sheriff pursuant to section 129D of chapter 127.
A detainee shall not be eligible to participate in this program if he is charged with: murder; any offense that carries the possibility of a life sentence; a violation of: paragraph (b) of 32 of chapter 94C; paragraphs (b), (c) and (d) of section 32A of said chapter 94C; paragraph (b) of 32B of said chapter 94C; sections 32B, 32E, 32F, 32J, 32K or 37 of said chapter 94C; a violation of section 13, 14, 15, 15A, 15B, 16, 17, 18, 18A, 19, 20, 21, 24B, 25, 26 or 26A of chapter 265; section 17, 34 or 35 of chapter 272; or an attempt to commit any offense referred to in these sections; or if he is detained under subsection (3) of section 58A of chapter 276. No sex offender, or sexually dangerous person as defined in section 1 of chapter 123A or any person who is charged with committing a sexual offense as defined in said section 1 of said chapter 123A shall be eligible to participate in this program. Placement of an individual in such program shall require victim notification as required under clause (t) of section 3 of chapter 258B.
Mass. Gen. Laws ch. 127, § 20B