The disappearance of Imbo and Petrone: FBI says people know who did it

PHILADELPHIA (KABC) -- On Feb. 19, 2005, a young couple left a bar in South Philadelphia -- and vanished.

For 15 years, the family and friends of Richard Petrone and Danielle Imbo, along with investigators from the Philadelphia Police Department and the FBI, have been trying to answer one question: what happened?

We take a look at the disappearance that has become one of the most intriguing missing persons cases in recent Philadelphia's history.