quick update
The next session has come and gone and I thought I'd share how things went down.
The party, after some soul searching, decides that they must face their accusers and attempt to divine why they were framed. They left the homocidial ranger behind while they attempted to negoiate their way into the city. Unfortunately, things didn't run smoothly.
The city guard was, strangely enough, guarding the gate when they came back through with wizard backup. Rather than allow a noncombatant into the fray they sent him away ... drawing the ranger into the fray.
He... in the player's words, "failed a saving throw" for what I'm still not sure, but he immediately placed himself in situation where not only did the wizard attempt to end his life, but his own party helped.
Consequently, the ranger is dead, slayed by his own friends who felt he'd crossed the line one too many times. The rest of the party is facing the original charges.. plus some other more recently added charges due to their escape.
Unfortunately for the party, as a direct result of their original actions it will be much more difficult to prove their innocence. I'm looking forward to seeing how they get out of it. (They're quite clever usually) and what character the player will bring in.
Thanks for the adivice, I'll update again once we play again... in a month.