Nicholas Logue and the guys at Paizo did a great job on Hangman's Noose! It is wonderful to see a module that is more atmosphere and role-play than it is hack/slash.
Now I know the module provides a method to run it for six players, but how about seven?
Hmmm...trying to think of which juror to nix. You could go a lot of ways really, though it's a hard choice. Also, with seven PCs, Old Mord's gonna get somebody! :-)
As an idea, rather than getting rid of NPC jurors couldn't you just say that juries in Absalom consisted of a number other than 12? You'll have to come up with more "visions", but probably not terribly difficult.
I know I'm keeping all of the jurors, myself. I'm running with the PCs as private eyes sent to investigate plot hooks leading to the haunted courtroom on The Night. I have 6 PCs and couldn't bring myself to nix any of the cool NPCs.
Eccentric suspects/victims make the mystery go 'round, don'tcha know?