Possible clues to the location of a bomb:
(1)
Displaced ceiling tile.
(2) Dust or dirt in an area typically clean.
(3) Chipping or scratching of paint, especially on a screw that had been painted over.
(4) Newly painted panel or surface.
(5) Anything moved or out of place.
(6) Recent construction or renovation.
(7) Something that has been recently delivered.
(8) Something that does not belong in the area.
(9) Sign of recent digging.
A person familiar with an area is invaluable since the person may recognize when something looks out of place.
