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.