Props

Props

Knife
Cameras
Notepad & Pen
Mask

A knife will be needed as it is the weapon of choice used by the Killer/Villain, sticking with Slasher conventions.

Cameras will be needed for the policemen to take pictures of the crime scene.
Notepad and pen for the  Secondary character/policeman to take notes from Main protagonist/Policeman.
A mask could be used, this would be to hide the Killers identity so he remains mysterious, sticking with Slasher conventions.