• 2008 Supreme Court ruling overturned DC ban on handguns
• Court reversed earlier decisions, ruling that the Second Amendment does protect an individual right to bear arms, independent of militia service
• Court emphasized that some kinds of limitations of guns would remain legal
• Heller decision applied only to DC; it is now unclear what standard should apply to state laws

The ruling was just vague enough to incite debate among gun-control and gun-rights groups for several decades. But the federal courts found the Miller decision clear enough to consistently reject claims that the Second Amendment protected an individual right to own and use guns. That is, until 2008. On 26 June 2008, the Supreme Court ruled in District of Columbia v. Hellerthat the Second Amendment does protect an individual right to own and use guns for lawful purposes, including self-defense. As part of this decision, the Court struck down parts of a Washington, D.C. gun law that banned all handguns from the city and required that all other guns kept in homes must be unloaded and disassembled or trigger-locked.

In the Heller decision, the Court emphasized that the individual right to bear arms was not unlimited; certain forms of federal regulation remain permissible. For example, the Court explicitly suggested that concealed weapons laws and bans on certain types of guns were not prohibited by the Second Amendment. The Court also declared that current laws forbidding certain categories of people, such as felons and the mentally ill, from owning guns were also permissible. But blanket prohibitions on entire categories of guns, such as handguns, that could be used for lawful purposes were not constitutional, nor were restrictions, such as the "unloaded and disassembled" provision of the Washington, D.C. law, that essentially prevented the use of a gun for lawful purposes such as self-defense.

The Heller decision marked a major victory for gun rights activists and a significant turn in Second Amendment law. But exactly how significant remains to be determined. Most importantly, since the District of Columbia is not part of any state, and it falls under the direct control of Congress, this ruling may have limited impact on similar questions in the states. The Court has always conferred far greater authority to the states than to the federal government to regulate guns, and the Heller ruling did not say anything directly about the connection between this ruling and state and local gun laws.