Мафия 4. The Smell of Money.

I don't have glass, but rather a precious stone, so it's unlikely that I'm the killer (probability 0%).

Heh. Glass is a weak clue...
Now, let's talk about cars and dragons.
Areg has a dragon.
And the peace symbol resembles the "Mercedes" emblem - an expensive car... I think Areg is involved in the murder.