Thriller Titles

This is a title opening of a thriller called "Se7en". The first thing that tells me it is a thriller is the use of sound, the music which is being used is dark and sinister which straight away let's the audience know that this is a thriller and not a romantic or a comic film. This title sequence is very dark, which may indicate that there me death, we see pictures of dead body, like as if they are files to a police investigation, this gets the audience thinking, why are is there pictures of dead people. What did catch my eye is, someone cutting there skin with a razor blade, this gets the audience thinking, is there a reason why there is someone cutting there skin, or is this a weapon which will kill or hurt someone in the movie. This only gets the audince to keep watching the rest,