The Second and Sixth Amendments

A puzzle for constitutional law buffs: I just read a recent case which explored the interaction between the Second Amendment and part of the Sixth Amendment. What is that interaction?

I realize, of course, that one can dream up all sorts of theories for how any two constitutional provisions might interact — but I’m looking for the one that the court actually discussed, and it also seems to me that this is indeed the most plausible such interaction, given the current interpretation of the two amendments.

UPDATE: Commenter tomhynes wins.