Venetica

Rogue Hunter: The guard captain in the amphitheater in the outer city will give you this quest. There are two Rogue Quarters in the outer city, houses that you must find and enter, then kill all the rogues within. They will attack you anyway, so this won't hurt your reputation toward the honorable ending. Once you've cleared out both rogue hideouts, go back to the captain to get credit and experience for the quest.

Fulfilling this achievement will also count towards the Rogue Nightmare achievement, which involves clearing all rogue quarters in the game in other parts of the city. You visit the outer city first, so this is the earliest place you can get Rogue Hunter.