The first appointment to the position of Resident Magistrate (RM), Bunbury (Leschenault) was signed at the Colonial Secretary's Office, Perth, on 14 March 1838, Henry Bull being the appointee ("Perth Gazette" 17 March 1838). Combined with the position of Resident Magistrate was that of the Sub-collector of Customs which remained so until 31 December 1900 when the Commonwealth became responsible for shipping and customs. Both positions were always held simultaneously by the same person.

In Series 4527, letterbooks, from June 1905 the signatory was the Clerk of Courts, Bunbury (Agency #1759), who also held the office of Government Land Agent and Treasury Officer. Letters over all titles are in the volumes. However, from volume 9 (1908-1909) to volume 21 (1916-17) W Lambden Owen signs as Resident Magistrate, with some volumes being dedicated to other functions of the office such as Electoral Registrar and Government Land Agent.

The local court for Bunbury was originally presided over by the Resident Magistrate.

(See also records for the Resident Magistrate Bunbury - Agency No. 1758).

In Series 4527, letterbooks, the signatory was Resident Magistrate until June 1905 from when the signatory was the Clerk of Courts, Bunbury, who also held the office of Government Land Agent and Treasury Officer. Letters over all titles are in the volumes. However, from volume 9 (1908-1909) to volume 21 (1916-17) W Lambden Owen signs as Resident Magistrate, with some volumes being dedicated to other functions of the office such as Electoral Registrar and Government Land Agent. It was the Clerk of Courts, Bunbury, who transferred the records to State Archives in 1947.