"When, as here, a law directly limits the private possession of "Arms" in a way that has no grounding in Framing-era practice, the Second Amendment requires that the law be subject to heightened scrutiny that considers (a) the practical impact of the challenged restrictions on the plaintiffÂ’s ability to possess firearms for lawful purposes (which depends in turn on the nature and functional adequacy of available alternatives), and (b) the strength of the governmentÂ’s interest in enforcement of the relevant restriction.

The court of appeals, by contrast, appears to have adopted a more categorical approach. The courtÂ’s decision could be read to hold that the Second Amendment categorically precludes any ban on a category of "Arms" that can be traced back to the Founding era. If adopted by this Court, such an analysis could cast doubt on the constitutionality of existing federal legislation prohibiting the possession of certain firearms, including machine guns. However, the text and history of the Second Amendment point to a more flexible standard of review."

The determination whether those laws deprive respondent of a functional firearm depends substantially on whether D.C.’s trigger-lock provision, D.C. Code § 7-2507.02, can properly be interpreted (as petitioners contend, see Br. 56) in a manner that allows respondent to possess a functional long gun in his home.

And if the trigger-lock provision can be construed in such a manner, the courts below would be required to address the factual issue—not fully explored during the prior course of the litigation—whether the firearms that are lawfully available to respondent are significantly less suited to the identified lawful purpose (self-defense in the home) than the type of firearm (i.e., a handgun) that D.C. law bars respondent from possessing.

To the extent necessary, further consideration of those questions should occur in the lower courts, which would be in the best position to determine, in light of this CourtÂ’s exposition of the proper standard of review, whether any fact-finding is necessary, and to place any appropriate limits on any evidentiary proceedings.

Moreover, even if the existing record proved to be adequate, initial examination of those issues is typically better reserved for the lower courts."

CONCLUSION
The Court should affirm that the Second Amendment, no less than other provisions of the Bill of Rights, secures an individual right, and should clarify that the right is subject to the more flexible standard of review described above. If the Court takes those foundational steps, the better course would be to remand."