Can a federal charge of unlawful possession of an unregistered firearm be considered an offence under the Sixth Amendment?

An exception to the offense-specific requirement of the Sixth Amendment occurs when the pending charge is so inextricably intertwined with the charge under investigation that the right to counsel for the pending charge cannot constitutionally be isolated from the right to counsel for the uncharged offense. See United States v. Cooper, 949 F.2d 737, 743-44 (5th Cir.1991) (holding that uncharged federal offense of unlawful possession of unregistered firearm was not inextricably intertwined with pending state charge of armed robbery involving the same weapon), cert. denied, --- U.S. ----, 112 S.Ct. 2945, 119 L.Ed.2d 569 (1992).