CNN reported the breakthrough on Wednesday, citing a source who has been briefed on the investigation.
The surveillance footage was from Lord & Taylor, but the source declined to specify what media outlet the television footage came from.
Furthermore, CNN reports that a federal law enforcement source said a a lid to a pressure cooker thought to have been used in the bombings had been found on a roof of a building near the scene.
Investigators, however, still don't know whether the attack was an act of foreign or domestic terrorism.
"If your experience and your expertise is Middle East terrorism, it has the hallmarks of al Qaeda or a Middle East group," former FBI Assistant Director Tom Fuentes said. "If your experience is domestic groups and bombings that have occurred here, it has the hallmarks of a domestic terrorist like Eric Rudolph in the 1996 Atlanta Summer Olympics bombings."
