Why would a terrorist announce he or she has a bomb? To test the reaction? A terrorist most likely tries to deal damage and get as far into transit as possible.

Why would a terrorist announce he or she has a bomb? To test the reaction? A terrorist most likely tries to deal damage and get as far into transit as possible. I can only imagine a real terrorist saying that to make the official more lax with their security check. So, I would respond by checking them more properly, but I would not threaten people with an arrest.