what are the symbols use in 12 Angry men

The jurors themselves can be seen as symbols; juror number eight for example symbolizes the open minded liberal, whereas, juror number ten symbolizes society's racism and bigotry.

We also have the little things........ the murder weapon (knife) was supposed to have been a symbol or proof of guilt but becomes the symbol of "reasonable doubt," the oppressive heat in the jury room a symbol of tension.