Sammy Gravano, notorious gangster turned FBI informant, reflects 30 years later

"Is there anything that I feel I regret and that I would do differently? Of course," said Gravano.

Almost 30 years after providing testimony that brought the powerful Gambino crime family to its knees, notorious gangster Sammy "The Bull" Gravano said he still has his regrets.

"Is there anything that I feel I regret and that I would do differently? Of course," Gravano told ABC News in a new special, "Truth and Lies: The Last Gangster," airing Thursday.

Despite a dramatic betrayal that turned Gravano against "the family" and brought down powerful Gambino boss John Gotti for good, no regret loomed as large as the ones about his real family, said Gravano.