"Exceptional circumstances
The IRCC website provides country-specific instructions on what documentation must be provided to that country’s policing agency in order for them to initiate the request for a police certificate.
Applications that do not include a required police certificate and do not provide supporting documentation where required should be rejected as incomplete.
The officer’s discretion may be required in assessing whether police certificates that do not fall within standard IRCC parameters may still be required to process the application. For instance, the war in Syria has made it extremely difficult for former residents to obtain a police certificate; officers may need to use discretion on how to best fulfill this admissibility requirement.
Some countries will not issue police certificates to applicants, and instead will only communicate directly with the relevant Canadian authorities. In such cases, existing IRCC procedures to obtain documentation should be followed.
In exceptional circumstances, some applicants may experience delays in obtaining police certificates within the 90-calendar-day timeframe allocated to submit a complete e-APR. In such situations, applicants should submit a letter of explanation as part of their application and include proof of having requested a police certificate (e.g., a copy of the receipt obtained when they requested the police certificate from the prescribed authority). The officer’s discretion may be required in assessing whether police certificates that do not fall within these time limits are valid and reliable for the purpose of evaluating admissibility."
http://www.cic.gc.ca/english/resources/tools/perm/express/intake-complete.asp