Culkin (Signs, You Can Count on Me) is the younger brother of actors Macaulay and Kieran. He plays film geek Charlie, who, along with Robbie (Erik Knudsen, right), organizes the school's cinema club. Charlie also has a not-so-secret crush on Hayden Panettiere's Kirby.
2 of 10
Emma Roberts, 20
The actress (Nancy Drew) is the daughter of Eric Roberts and the niece of Julia Roberts. In Scream 4, she plays Sidney's cousin Jill, who finds herself in a heap of danger when Ghostface starts ringing her up.
3 of 10
Marielle Jaffe, 21
Jaffe (Percy Jackson & the Olympians: The Lightning Thief) plays Olivia, who is BFF with Jill and Kirby. She lives next door to Emma Roberts' Jill — which might not be a great location given Ghostface's return to town.
4 of 10
Hayden Panettiere, 21
Best known for playing indestructible teen Claire Bennet on NBC's cult series Heroes, Panettiere portrays a much more normal high schooler in Scream 4. Her sharp-witted Kirby is also a closet movie buff.
5 of 10
Erik Knudsen, 23
Knudsen (Scott Pilgrim vs. the World, Beastly) plays Robbie, a nerd who, with Charlie, helps Gale and Sidney break down the new ''rules'' for survival in a horror film.
6 of 10
Nico Tortorella, 22
Tortorella appeared on the short-lived CW series The Beautiful Life: TBL and most recently on ABC Family's Make It or Break It. In Scream 4, he's Jill's dreamy but unfaithful boyfriend, Trevor.
7 of 10
Alison Brie, 27
Sidney returns to Woodsboro with a new book and a publicist, Rebecca, played by Community's Brie. Bitchy Rebecca works for Sid but is actually a giant fan of Gale Weathers.
8 of 10
Marley Shelton, 37
Shelton (Grindhouse) plays Det. Judy Hicks, who works for the Woodsboro police under Dewey, whom she may have a tiny crush on. The somewhat odd Judy also went to high school with Sidney.
9 of 10
Anthony Anderson, 40
Anderson also appeared in Scary Movie 3, which is the spoof franchise based on the Scream flicks. In Scream 4, he's Deputy Perkins who works with Adam Brody's Detective Hoss to protect Woodsboro citizens from Ghostface.
10 of 10
Adam Brody, 31
Best known for his role as übergeek Seth Cohen on The OC, Brody portrays Detective Hoss, an inept member of the Woodsboro police who resembles a younger version of Dewey.