Who Is Killing the Gold Cloaks in House of the Dragon S3E5?

In House of the Dragon Season 3 Episode 5, Daemon Targaryen (Matt Smith) raises an alarming new crisis at Rhaenyra's council: members of the Gold Cloaks city guard are being murdered one by one. The council is already divided over funding shortages, Aemond's dragon Vhagar, and Ormund Hightower's seizure of Tumbleton. The killer's identity is not yet revealed.