How suspense is created

The opening of 'The Stepfather' is a flashback to what has happened just before the film commences. In it we see what the 'father' has done to his first family. From this the main character goes on to become stepfather to a new family.
We are introduced to the main character - we see him calmly walking into the bathroom. The mise en scene reveals nothing out of the ordanary, however the music at this point shows the audience that there is some ambiguity. We see him wearing plastic gloves and dying his hair. This on its own is not suspisous, but when we see him shaving off his beard and putting one coloured contact lens, we realise that he might be trying to alter his appearance. At this point the audience is not sure what genre the film could be. However the sinister music makes us uncomfortable. Next we see the main character go into the kitchen and the first thing he does is put on a christmas carol- 'Silent Night', this is ironic because we later discover that he has had anything but a silent night. The sweet innocent sound of the choir is completely at odds with thechilling events that have occurred.
The Step father calmly makes some breakfast and then suddenly the camera tilts to show his dead son lying on the table. This is the first evidence of the action thriller genre. The camera focus's on him tiding up the mess that has been made, cleaning up the childrens toys, possibly suggesting his way of thinking and how hes trying to make everything seem normal again. Then the camera pans around the room showing his dead wife and children laying on the floor, the camera then stops on the sink where on one side it shows dirty mugs and plates and in the other basin shows blood coverd utensils including a hammer knifes and a meat basher. With the camera panning and tilting it graduly revels the horrific truth, the dreamtic tilt of the camera as well as the slurring of the music indicates the point at which the narrative switches.
The mise en scene is ironic The house is decerated with christmas decorations and full of presents both of which should represent a happy festive family sence, however even though some of the presents had been opened and possibly there had been some happiness it ended in mass murder. Looking back even the bathroom scene contains some references to what was going to happen later, in that he uses sharp sizzors and blades which although everyday objects, actually could be used as weapons. The use of flashbacks towards the end of the opening show screaming which at first could be sounds of excited children in a playground, you then later discover its the sound of his teenage daughter struggleing with her attacker. This use of flashback is a way that editing can be used to clarify the narrative and gives a bit more detail.
The combination of ironic mise en scene, sinister and angelic music, the tilting and panning of the camera and the use of horrific revealing flashbacks all contribute to the creation of suspense in an appreantly normal enviroment.