It was created on May 22, 1868, in response to the assassination of Thomas D'Arcy McGee, a prominent Irish-Canadian politician and MP for Montreal West, in Ottawa on 7 April.

[3] McGee was killed by elements of the Fenian Brotherhood, a powerful Irish nationalist organization based in the United States, in the new federal capital less than a year after Confederation.

The Canadian authorities were worried about the power of the Fenian Brotherhood, which had already launched three major raids into Canada in 1866 before McGee's death, and that existing law enforcement agencies were not capable of protecting state security.

Its primary functions were: They gradually also acquired responsibilities for compiling fingerprint and criminal records, and administering a parole service.

[9] The Dominion Police consisted of Commissioners and constables appointed for that purpose, and its authority extended over the provinces and all parts of the territories not patrolled by the RNWMP.