Ismark knows that Dareios' supposition is essentially correct. The Burgomaster, Kolyan, was sherrif, mayor, and rent collector for Count Strahd von Zarovich. The Burgomaster was the only village official. Normally Count Strahd von Zarovich would appoint a new Burgomaster after the previous one's term of office ends, but he has not done so yet. The Count rarely leaves his castle and has not been seen in the village since Kolyan died.
It is forbidden by law to trespass in the Count's castle without an invitation (one of the few laws in Barovia that carry the death penalty). Besides that, the castle is reputed to be abandoned (only the Count and an aged man servant live there, neither is capable of maintainance) and haunted. As far as Ismark knows, nobody has traveled to the castle to inform the count of the Burgomaster's death.
Since Kolyan died, the villagers have looked to Ismark for decisionmaking on issues of importance.