Scharn is the Entharan magistrate in Retrospect who examines Seven of Nine's accusation that the arms trader Kovin assaulted her and extracted Borg nanoprobes, and who finds no evidence to support it.
Scharn is a magistrate of the Entharans, a trading people with whom Voyager does business in the fourth-season episode Retrospect.
After Seven of Nine, guided by the Doctor's attempt at recovering repressed memories, accuses the weapons dealer Kovin of violating her, Scharn is called in to conduct the inquiry. He warns Janeway that among his people even an accusation can destroy a trader's livelihood, but allows Kovin's laboratory to be examined.
The evidence turns out to have an innocent explanation, yet by then Kovin has fled in panic. Scharn helps Voyager try to reach him before his overloaded ship explodes, and the affair ends with the accusation unproven and the accused dead.