Former FBI agent Tanya DeGenova told Daybreak the release of the CCTV images is "extremely important for the people who live in Boston and globally".
She said: "At this point we don't know whether is these [people] are home grown terrorists or if they are foreigners who have come to the United states, and they could be anywhere".
New photos of the suspects identified by officials as Dzhokar A. Tsarnaev, 19 and Tamerlan Tsarnaev, 26 have been released.
The FBI has released pictures and video of two suspects in the Boston Marathon bombing, seeking the public's help.
President Obama attended a memorial service in Boston today, paying tribute to the victims of Monday's terrorist attack.