I don't think it's possible to know that. I also am not 100% sure the murderer was racist. Perhaps there is a 60% chance he hated her because of the color of his skin. Maybe he was delusional. We don't know. Wr also don't know if racism could have prevented this. People can walk in trains. Maybe the voices in his head told him to stab the first blonde he saw. When I saw the video it reminded me to be more aware of my surroundings. I don't want to limit myself to one variable.