Ex-FBI agent who worked on secret 9/11 case says hijackers had a U.S-based support network

Nearly 20 years after the 9/11 terror attacks, some victims' families are still pressing the U.S. government for more information on possible ties between Saudi leaders and the attackers. CBS News spoke exclusively with a retired FBI agent who was part of a still-secret investigation into the hijackers' network inside the U.S. Catherine Herridge reports