I've spoken with Inspector Tarem regarding the evidence you gathered from the ruins of the Shady Rest Inn. He seems certain that the hoofprints and the shield you found there point to the Grimtotem clan of tauren.
With reports of Grimtotem activity on the rise in the marsh, this has to be more than a mere coincidence. I'm sending you to speak with Captain Darill, who is something of an expert on the Grimtotems. Follow the road north out of town to North Point tower. It's the second outpost on the road.
Captain Vimes thinks the Grimtotems are behind the destruction of the Shady Rest Inn? That wouldn't have been first on my list of suspects, but if Captain Vimes sent you here to follow up on a lead, he must have his reasons. Regardless, the Grimtotems have been a thorn in our side for some time and we're always glad for the extra help.
At least the following quests must all be complete before Vimes will offer this quest:
This is part of The Shady Rest Inn quest chain: