The Purloined Letter Theme of Lies and Deceit

The truth is buried so far down in "The Purloined Letter" that you'd need a backhoe to unearth it. Everyone in the story weaves deceptions: the royal lady, D—, G— (his little trick with the muggers), and Dupin (the green glasses). Even our narrator isn't totally straightforward, because why else would he need to be so cryptic about everything? Is he withholding evidence—or is he just putting us in the position of the detectives, sifting through evidence to get to the truth in a world that doesn't much value it?

1. Does "The Purloined Letter" seem to have an ethical position on lying? That is, does anyone in the story seem to believe that lying is actually wrong?
2. Who seems most trustworthy in the story? Are all of the characters lying, or do some of them tell the truth?
3. Does the story appear to draw a distinction between lying and withholding information? Which characters deceive through lying, and which ones simply fail to provide all the relevant facts?

D— did not actually deceive anyone; he simply counted on the royal man's inability to notice what was obvious.

Because the royal lady's deceit sets the entire plot in motion, she is the story's most culpable villain.