To my understanding, the main film genre 'Thriller' consists of many sub-genres and these sub-genres are:
Crime thrillers- This sub-genre of thrillers contains elements of both crime films and thrillers respectively, these particular films offers story lines based on either successful or non successful crimes which undoubtedly creates large amounts of suspense and excitement. These films more or less focus on the criminals in comparison to the police force-and these types of film often consists of criminal behavior such as murders, robberies, assault, etc. A good example of crime thrillers is most noticably 'Seven' which stars Morgan Freeman, Brad Pitt and Gwenth Paltrow, respectively.
Spy Thrillers-This sub genre consists of the protagonist or in some cases, protagonists who are normally agents which are employed by a government . This specific sub genre was arguably popularised and established in the British Cinema were great British directors (most noticably Sir Alfred Hitchcock) contributing greatly to this. The most obvious and simple example of this sub genre is the James Bond films.

Psychological Thrillers- This sub genre consists of the conflicts between the protagonists and the antagonists does not usually involve violence, but the conflicts are indeed mental. in these types of films, characters do not necessarily need their physicality to beat their enemies, but would rely on their mental strength, or in some cases, their mental stability.
Sir Alfred Hitchcock is known for the successful psychological thrillers he himself directed, these films include, 'Psycho', 'Shadow of a doubt' and 'Suspicion' respectively.

Legal Thrillers-This sub genre consists of the main characters as lawyers and people in those sectoral departments. The ideology of Justice normally is the central point in which the film surrounds. This sub genre of thrillers are not as common in comparison to popular thriller sub genres such as spy thrillers and crime thrillers. Most notable examples of legal thrillers are 'The Pelican Brief', 'The jury' and 'The lincoln lawyer' respectively.


