He is half African-American, half Italian. His mother was an opera singer, and his father was a stagehand/carpenter from Naples, Italy.
His mother was doing a nightclub gig on a split bill with Josephine Baker in Copenhagen around the time he was born.
Lived in Europe, New York City, and Cleveland until he, his older brother, Vincent, and their parents moved Manhattan when Giancarlo was six. During the boys' teens, the family lived in Elmsford (Westchester County), New York.
Two children, with McManigal, Shayne (b. 1997) and Kale (b. 1998)
Is a member of the Atlantic Theater Ensemble. Atlantic Theater is the theater company started by David Mamet and William H. Macy.
He has won two Obie Awards for his performances in Distant Fires and Zooman and the Sign.
Was member of the dramatic jury at the Sundance Film Festival in 1997.