Massachusetts law..
an individual with a valid firearms identification card issued under G. L. c. 140, § 129C, is not obliged to secure or render inoperable a firearm while the individual carries it or while it remains otherwise under the individual's control. A gun owner may therefore carry or keep a loaded firearm under his or her control in his or her home without securing it with a trigger lock or comparable safety device. The gun owner's obligation to secure the firearm in accordance with the statute arises only when the firearm is stored or otherwise outside the owner's immediate control