In Terminal 3 of ORD on Sunday, it appeared that one of the TSOs was touching buttons and/or making some adjustment at the top of the precheck WTMD. Does anyone know what they were doing? I did not think that this was a good sign and was happy to have someone else go through the WTMD before me, thinking that perhaps it meant that a random beep was going to come shortly afterward. The person in front of me went through with no issue so I went through and also had no problem. The person after me got the random beep and was sent through the body scanner. They also called for a male assist for him and while I am not sure what happened, my guess is that he probably had something in his pocket that alerted the body scanner that one is supposed to be able to keep in one's pocket while going through precheck.
I was wondering about whether the adjustment at the top of the WTMD perhaps changes the frequency of the random beep?
Himeno, when you mentioned that there were random hand swabs in the precheck line, do you mean that people with the random beep received hand swabs or was this separate?