The Second Amendment protects an individual right to possess a firearm unconnected with service in a militia, and to use that arm for traditionally lawful purposes, such as self-defense within the home. Pp. 2–53.
(a) The Amendment’s prefatory clause announces a purpose, but does not limit or expand the scope of the second part, the operative clause. The operative clause’s text and history demonstrate that it connotes an individual right to keep and bear arms. Pp. 2–22.
...
The handgun ban and the trigger-lock requirement (as applied to self-defense) violate the Second Amendment . The District’s total ban on handgun possession in the home amounts to a prohibition on an entire class of “arms” that Americans overwhelmingly choose for the lawful purpose of self-defense. Under any of the standards of scrutiny the Court has applied to enumerated constitutional rights, this prohibition—in the place where the importance of the lawful defense of self, family, and property is most acute—would fail constitutional muster. Similarly, the requirement that any lawful firearm in the home be disassembled or bound by a trigger lock makes it impossible for citizens to use arms for the core lawful purpose of self-defense and is hence unconstitutional. Because Heller conceded at oral argument that the D. C. licensing law is permissible if it is not enforced arbitrarily and capriciously, the Court assumes that a license will satisfy his prayer for relief and does not address the licensing requirement. Assuming he is not disqualified from exercising Second Amendment rights, the District must permit Heller to register his handgun and must issue him a license to carry it in the home. Pp. 56–64.
EDIT: And grab Jinx on your way, looks like his meter got knocked around a bit too. 
