paris and brussels are still on high alert this evening. and so are many cities back here at home ahead of the holiday this week. out on the campaign trail, the fight against isis has become a make or break topic for the presidential candidates. also tonight, argentina jeanne shaheen will be on the show to talk about this country's heroin epidemic and her call for congress to pledge millions to save lives. but we start with the latest on the investigation into the paris terror attacks. chris jansing is in paris. keir simmons is in brussels. kelly o'donnell is at the white house where the french president will meet with president obama tomorrow. and pete williams is in washington, tracking how cities across this country are reacting in the wake of new threats. let's get right to the latest developments, the paris prosecutor confirms today that an explosive belt without a detonator, has been found in a paris suburb. it was apparently found in a