As in some other jurisdictions, what most people think of as "false imprisonment" is categorized as kidnapping in Massachusetts, codified at Chapter 265, Section 26:
Whoever, without lawful authority, forcibly or secretly confines or imprisons another person within this commonwealth against his will, or forcibly carries or sends such person out of this commonwealth, or forcibly seizes and confines or inveigles or kidnaps another person, with intent either to cause him to be secretly confined or imprisoned in this commonwealth against his will, or to cause him to be sent out of this commonwealth against his will or in any way held to service against his will, shall be punished by imprisonment in the state prison for not more than ten years or by a fine of not more than one thousand dollars and imprisonment in jail for not more than two years. Whoever commits any offence described in this section with the intent to extort money or other valuable thing thereby shall be punished by imprisonment in the state prison for life or for any term of years.
Separate from the criminal offense, Massachusetts courts also recognize civil actions for false imprisonment.