parameter. they're trying to narrow it around known locations, known accomplices. given his brother lived here, given the man that those authorities in france dealing with the investigation believe was the mastermind of this, he lived only a few streets away from where i'm standing now. they feel quite comfortable in focusing their investigations on this neighborhood. parameter.a very narrow there is so much at stake. one of the concerns we're hearing time and time again and seeing with our own eyes with the heavy presence of those anti-explosive squads and anti-bomb robots is this concern that given the way this attack was carried out and the use of suicide vests that prosecutors, authorities, the police officers on the front lines of this, that they're having to go very slowly and tread very carefully, kate, because there's, of course, a lot of fear about what they might find when they do find that eighth attacker.