Conducting Background check for USA applicants is very easy for Canada. USA has already done all the hardwork of strigent security checks, before they gave access to a person to reside in USA. Security records that are reqd later on, are given by the FBI as and when reqd or requested. So Canada has a cake dressed already and in their hands and all they need to do, is to put a cherry on top
and this reduces the background check time (IP2) dramatically for usa residents unlike residents from other countries.