C. 140 § 131L (Massachusetts Firearm Laws) Weapons Stored or Kept by Owner
Remember this is very important (a) It shall be unlawful to store or keep any firearm, rifle or shotgun including, but not limited to, large capacity weapons, or machine gun in any place unless such weapon is secured in a locked container or equipped with a tamper-resistant mechanical lock or other safety device, properly engaged so as to render such weapon inoperable by any person other than the owner or other lawfully authorized user. For purposes of this section, such weapon/ firearm shall NOT be deemed stored or kept if carried by or under the control of the owner or other lawfully authorized user.
