So ran into a big bug. Went to do the Canthar/Sarah quest. Turned him in for trying to take over Sarah's stall. In jail went to see him and killed him. Later he still managed to spread word I was a convict (the quest still continued) and after time everyone turned against me. EVEN THOUGH HE WAS DEAD he passed the word. Now, I can't pay the 500 gold to him to clear it up, so im stuck with the merchants against me, upper quarter.

Any idea? Way to far into the game to reload a save. Any way to spawn him alive again. Any way to clear the quest.

Is his corpse still there ?

if its there you can activate the cheat mode (press b and type "marvin" and press b again). Then you can swap into his corpse with "k". Then press F8.

But i remember when you reach the next chapter, the game remove all dead bodies.

I think there is nothing you can do except load an old Savegame