Players can kill these during The Branches of Darkmeyer quest to gain status. They give 2 status per kill, and will respawn a short while after death. They can be killed without a Darkmeyer disguise, as they're fenced in and the jail guards can't fight you, but you will not receive any status. After you kill 60 captured Meiryerditch citizen, you will have gotten all the status attainable from killing citizens.