Bieber made his fictional TV debut with a two-episode arc on "CSI" last year, and according to co-star Marg Helgenberger, the kid who played a troubled teen was, off-camera, a trouble-making teen.
"I shouldn't be saying this but he was kind of a brat [on the set]," Helgenberger told French Magazine Le Grand Direct Des Medias.
"He was very nice to me," she continued, "but he locked one of the producers in a closet.
