Not true for US. Returning citizen needs to go through immigration first, collect luggage and only then hand in the customs form to the officer. Questioning depends on ?????

After all these years, I really can't figure it out, but it ranges from handing in your form and walking to actually being send for secondary, my first time ever about 2 months ago in DFW, coming back from Japan. My form was marked as possible "commercial" by the form collecting agent, even though I told the agent that I was there for a long, touristy weekend.