Right now, a criminal has no incentive to make reparations, because he can still be summoned after he does it. If settling the matter erased the scents, things might be a bit different. Now, I did name the thread Weregild, but I think that a single system could be used for all the crimes, not just murder.
Anyway, the victim of a crime (or his direct descendant, in case of murder) should be able to build some kind of a warning thingy (skull on a pike or something like that) and put copies of scents in it. He should also put a price on it, much like in stalls. In addition to money, stolen items could also be listed in the price (ie items that the scents point to). If the criminal pays the full price, all the scents (and all the other copies of them, as well as the harvestable scent at the crime site) disappear. The victim can collect his due at the warning thingy, and everyone walks away alive.