Research into genre-horror

Definition

Horror is a film genre seeking to pick out a negative emotional reaction from viewers by playing on the audience's primal fears. Horror films often feature scenes that startle the viewer; the supernatural are frequent themes. Thus they may overlap with the fantasy, supernatural and thriller genres.

Horror films often deal with the viewer's nightmares, hidden fears and terror of the unknown. Plots within the horror genre often involve the intrusion of an evil force or an event into the everyday world. Prevalent elements include ghosts, aliens, vampires, werewolves, curses, satanism, demons, gore, torture, vicious animals, monsters, zombies, cannibals, and serial killers. 

History
1890s-1920s- The first depictions of supernatural events appear in several of the silent shorts created by the film pioneer Georges Méliès in the late 1890s, the best known being Le Manoir du diable, which is sometimes credited as being the first horror film. Another of his horror projects was 1898's La Caverne maudite (aka, The Cave of the Unholy One, literally "the accursed cave"). 
In 1910, Edison Studiosproduced the first film version of Frankenstein, which was thought lost for many years. 

Sub-genre

The sub-genre of our horror film is stalker/serial killer as the lead male character will be stalking the three girls on a hunt to kill them. He is a serial killer with an aim to just kill the girls

An example of a film including a serial killer is Scream, the man in the mask named 'Scream' is a stalker and serial killer, whose aim is to kill mostly teenage girls and boys after spying on them and stalking them beforehand. 

Characters
Characters in serial killer films usually include a victim or victims and one serial killer or a group, ours includes three victims and one serial killer.
Victims: Victims are usually young and vulnerable with one person who sees them self as a hero and stronger that the rest. There is also usually a victim who is much weaker and helpless, and you often find a relationship going on between two characters, that is unfortunately ruined as the plot goes on. Our victims are less conventional as there will be three vulnerable girls and no boys or love interests, just one weaker girl who is attacked at the beginning.
Serial Killer: The serial killers usually lack any compassion or care, they are tough and fierce and are created to frighten the audience when they least expect it. They cause the horror and ruin the victims lives, they also usually wear a disguise, as in a costume or mask and are usually male. Ours will be male which is conventional and will wear some sort of disguise on his face.
Music
Horror music is made to build up tension and cause a build up and make the audience expect something is coming.
Horror music can be screeching, pianos and music that is quiet to begin but builds up.
Sound effects also