Initially comprising 12 men, the Dominion Police were responsible for the protection of federal government buildings, including the Parliament.

Six members of the RNWMP also left to form the first dedicated parliamentary protective unit, with three assigned to the Senate and three to the House of Commons.

During their early years, the service's members gave guided tours of the Parliament and sold information booklets to the public.

[7] On October 22, 2014, Michael Zehaf-Bibeau evaded security and entered the Hall of Honour with a rifle and a knife after fatally shooting Corporal Nathan Cirillo of The Argyll and Sutherland Highlanders of Canada (Princess Louise's), injuring a constable.

A member of Parliament pointed out that not all of the officers in the unit spoke French, creating a potential for problems when directing the public during an emergency.

[17] In late January to mid February 2022, demonstrators occupied the downtown core of Ottawa, including much of the Parliamentary Precinct.