Heat Vision is reporting that Adam Brody, Marley Shelton and Erik Knudsen have joined Scream 4.

This new installment brings together Wes Craven and Kevin Williamson, who made the original Scream in 1996. Also coming back are Neve Campbell, David Arquette and Courteney Cox.

Brody is going to play a cop who recently graduated from college and who was raised on the CSI TV series.

Shelton will take on the role of a deputy who knew Neve Campbell's character in high school.

Knudsen will have a role similar to the one played by Jamie Kennedy in the first two films. This was a character "who is familiar with horror movie conventions and a provider of comic relief."

In order to hide who the killer in this film is at a reading of the script this week, the actors were instructed to stop reading at page 75 to prevent even those already cast from knowing what happens.

Also, Ghouls On Film is reporting that Lauren Graham has left Scream 4 "due to date conflict and script changes." She was playing the mother of Jill Kessler (Emma Roberts) in the film.

Shooting began this week in Michigan.