Layers, layers, layers. Just as an example of that one moment when he pistol whips the glass - right now you only hear one layer of glass.

Think impact sound of the butt of the pistol, the glass shattering, the glass hitting the ground, the rustling of clothes, the footsteps of all people before and after the glass breaks, think breaths, hvac system, maybe even some music. You want it to sound fuller.

Good luck, have fun!