From USA v. Huitron-Guizar:

The right to bear arms, however venerable, is qualified by what one might call the “who,” “what,” “where,” “when,” and “why.” For instance, it is unlawful to knowingly receive guns with obliterated serial numbers, see 18 U.S.C. § 922(k); United States v. Marzzarella, 614 F.3d 85, 100-01 (3d Cir. 2010). A juvenile, with some exceptions, cannot possess a handgun, see 18 U.S.C. §922(x), United States v. Rene E., 583 F.3d 8, 16 (1st Cir. 2009). An airline passenger may not carry aboard a concealed firearm, see
49 U.S.C. §46505, United States v. Davis, 304 F. App’x. 473 (9th Cir. 2008).
Nor may a drug dealer use or carry a weapon to protect his stash, see 18 U.S.C. §  924(c), United States v. Jackson, 555 F.3d 635, 636 (7th Cir. 2009). Our issue concerns the “who.”

This analysis tracks exactly with the framework I proposed in The Constitutionality of Social Cost on pp. 1034-1036.

When confronting laws implicating the Second Amendment, it is helpful to consider five questions—what, where, when, who and why.

First, what type of arms can a person keep? . . . .

Second, where can a person keep and bear arms? This question addresses the next front in Second Amendment cases involving carrying a firearm, perhaps concealed, outside the home . . . .

Third, when would a person be permitted to bear arms—more precisely, with what type of delay may an individual’s exercise of the right be burdened?

Fourth, who can keep and bear arms—law‐abiding citizens, minors, violent misdemeanants, non‐violent felons, violent felons? Fifth, why is the right to keep and bear arms being restricted? I combine these two inquiries because in the context of
social cost and the Second Amendment, they boil down to the same question: should this person be able to exercise his Second Amendment rights?

I hope my work influenced the court’s opinion.