The incident took place on the eve of the holiday of Shavuot: During that time there were no Knesset members or employees in the building.
At first, the Knesset's guards thought that a floating plastic bag was the culprit, but this theory did not explain why the electronic alarm system was triggered.
"Maybe this is a ghost from the burial plot found in the Knesset during the construction of the new wing," one Knesset source suggested with a smile. "And maybe it is the ghost of a former politician. After all, it is difficult to leave a place like the Knesset…"
The Knesset's security personnel believe that there is a more rational explanation: A white object, perhaps plastic, dragged into the camera's range, created the effect of a ghost. The computer that sets off the alarm is highly sensitive, and therefore it also warned about the incoming white object.