Originally Posted by daniellam

I would say this is the problem. Canada seems to be the only country where the immigration officer and the customs officer is the same person.

In other countries, the first person you see is the immigration officer where all you do is establish your identity and see if you can enter the country (hence the "scan passport", "look at your face" and "wave you through", and "no further questions" thing in most other foreign countries). Note: No customs questions are asked at this point.

Then you would go claim your bags at the baggage claim.

When exiting the baggage hall, that's when the customs examination would start. If you have stuff to declare, you go to the red lane, if you don't have stuff to declare you go to the green lane. In some countries such as Australia, if you go to the green lane, all your bags automatically get x-rayed. The customs officers during that stage would see if you are acting strange, nervous etc. and determine whether they need to pull you over for a full baggage inspection.