I've read this somewhere and thought that it may be interesting ... it talks about the process of conducting security clearance:
Security & Criminality Checks:
A part of the b/ground checks is the 'Security Check'. It commences after our med results are submitted to the CHC. This is a major activity -mainly concerning our 'safe inclusion' into the Canadian Soil; vis-a-vis, Political, Socio-Econmical, Anti-Social disposition, perceived Threat to Canada's integrity etc. This gets us the SDEC, CDEC & SECCRIM.
This is a serious & time-consuming stage, involving many agencies, including CSIS, Interpol, NASC, Database Checking & touch-base with Local Police. Many things are considered here... the No. of countries visited, Applicant coming from 'certain' countries, ex-Servicemen [including Law Enforcement services], Prolonged stay in a country w/out sufficient docs to prove cause, frequent traveling to certain nations, your *Name (?), Inter-Religion/Nationality Marriages etc.
If everything is simple & straight, the file soon gets into the 'final review' stage. If there are any 'red flags', our case goes into a 'spin'. Then our file might go to the local Police/CID agencies; the outcome/timeframe of which is beyond the control of CIC. And thereby the timeframe can be anything [sometimes beyond 1yr]. But, usually this stage should be over by 5 months max. However, a point to be noted is that we can also be called for an Interview [at this stage], due to this reason.
Cheers,
Patient