Originally Posted by SATTSO

It's very rare. Only when the pax has become so disruptive to the screening process and causes a disturbance at the checkpoint. Most often what I have seen, and been a TSO involved in, the pax ask for a STSO, still refuses screening of their property, a LEO is summoned, and the LEO basically says (my words now) screening will continue, TSA will finish their procedures, then you can leave. The LEO stays and watches, but that's about it.