Thank you for the reply. So, do they route passengers to formal passport control, or do they just send border guards to meet the plane by the jetway and then select passengers "randomly" for additional questions?
In this instance we walked past the old passport desks, which have been decommissioned, but the border agents were stamding by them, checking all IDs from all non domestic flights. I mistakenly pulled out my UK passport rather than my French passport, and that was given some extra checks. It didn't take more than a few minutes though.