Key conventions of a gangster thriller: Desmond

Cinematography: close ups and extreme close ups of the protagonist character, this is often to show their inner emotions, also it can be used to focus on key props to aid the narrative.

quick shots to hide identity, low key shot or shadow of the character. 

Editing: jump cuts and cross cutting are key features which are essential to build suspense and mystery.

Sound: music is essential to understand the mood of characters or a hint at a significant part in the film. It also adds suspense and tension to make the shots more dramatic for the audience.

Mise en scene: the location is important for the film because it helps the audience establish the theme. 

lighting is often low key 

costumes - antagonist will be in dark clothing. Protagonist will be in ordinary everyday clothes