who was the killer in scream 3

The killer in Scream 3 is Roman Bridger, who is Sidney Prescott's half- brother. Roman was the director of the film "Stab 3" within the movie and acted alone as Ghostface. His motive was revenge against Sidney and their mother Maureen Prescott for rejecting him after he was born from Maureen's assault and given up for adoption. Roman orchestrated the murders in Scream 3 to frame Sidney and avenge his past. Sidney ultimately defeats Roman after a final confrontation, and he is killed by Dewey Riley.