Originally Posted by bocastephen

When the line is closed, the agent is supposed to give you a passcard that you show to the agent at the x-ray machine, and they let you leave on your shoes, and liquids/etc in the bag. You need to ask for it at the ID check desk, once you get to the x-ray, it's too late.

Of course, you've discovered another issue - this is JFK and no one there really gives a crap about anything or anyone.