An image of a check written by a victim shows Oklahoma City misspelled as Oaklahoma City.
When the medical examiner is explaining the precision work of the unsub to Prentiss and Reid, she uncovers one victim's face and reaches for the victim's eye. As she does so, the victim's eyelid quivers ever so slightly, probably in reaction to the slight touch on her eyelashes.
The car park scene at beginning is clearly Canada and not US as a sign behind the victims read 'Theatres' Canadian/British spelling rather than US 'Theaters' spelling. Vancouver is one of the known filming locations.
The roads given as the unsub's location, Motor and Descanso, are in LA, not Oklahoma City.