2. Shadows cast on actors

3. Mirrored shots

4. Frosted glass

5. Characters faces obscured

7. Corrupt police usually feature

8. Greed and jealousy usually a motivation

9. In more modern noir, serial killers with strange motivations play a big part

10. Usually contains adulterous affairs

11. Usually has a grim look at the world

13. Alcohol is another common prop

14. Guns

15. Smart dress costumes (suits fedora etc)

16. Neon lights at night

18. Maze like streets

19. Dark corridors etc.

20. Police headquarters are a common setting in noir

22. Classical Jazz music.