Space Security Service
The Space Security Service or SSS was a force in operation circa 4000 in order to gather intelligence relevant to the safety of the Solar System and, when necessary, eliminate threats to that safety. They considered the Daleks paramount amongst these threats.
Overview
The SSS had its headquarters in Central City on Earth where computers contained records of the chemical makeup of every person in the Solar System. (DW: The Daleks' Master Plan) The SSS also had branches in other places, like Carrington City on Micawber's World. (EDA: Placebo Effect)
Agents wore uniforms and carried blasters. (DW: Mission to the Unknown) The Service had a rank system, with First Rank achieved some time after an agent joined the serviced and Second Rank having greater responsibility. (DW: The Daleks' Master Plan) One agent, Marc Cory, carried with him two documents, one giving him license to kill, the other the power to enlist any person to aid him in his mission. This included civilians. (DW: Mission to the Unknown)
Agents could rarely afford to have sentiment or compassion. Sara Kingdom, a Space Security agent, killed her own brother, Bret Vyon, also an agent, on orders. Though Kingdom herself got her orders from Mavic Chen, the Guardian of the Solar System, the Space Security itself considered no one above suspicion, including Chen himself. (DW: The Daleks' Master Plan)