Mass. Gen. Laws ch. 266 § 14
Whoever breaks and enters a dwelling house in the night time, with intent to commit a felony, or whoever, after having entered with such intent, breaks such dwelling house in the night time, any person being then lawfully therein, and the offender being armed with a dangerous weapon at the time of such breaking or entry, or so arming himself in such house, or making an actual assault on a person lawfully therein, shall be punished by imprisonment in the state prison for life or for any term of not less than ten years.
Whoever commits any offense described in this section while armed with a firearm, as defined in section 121 of chapter 140, shall be punished by imprisonment in the state prison for life or for any term of years, but not less than 15 years. Whoever commits a subsequent such offense shall be punished by imprisonment in the state prison for life or for any term of years, but not less than 20 years. The sentence imposed upon a person who, after being convicted of any offence mentioned in this section, commits the like offence, or any other of the offences therein mentioned, shall not be suspended, nor shall he be placed on probation.
Mass. Gen. Laws ch. 266, § 266:14