The Science Police were an agency present within the Terran Empire of the mirror universe. They were known to had apprehended a trio of surgically altered Romulan spies that had attempted to infiltrate the mining camp on Rigel XII.
On another incident, Terran security forces had apprehended a previously mysterious species known as the Breen and were waiting for the Science Police to arrive in order to make adjustments to the universal translator. However, before they could do so, the Breen had transported outside his secure cell by unknown means. (Decipher RPG module: Through a Glass, Darkly)