Exactly. Just look at the Green River Killer. He’s not well known, but he killed 50 young women, mostly white, but also mostly runaways and sex workers.
But even if he's not as well known as Zodiac, again, look at the victim profile: runaways and sex workers. It's not just about skin color, although for some reason both of you zeroed in on that. I specified "marginalized groups" such as [mostly black] runaways. It's about being poor, unknown, and not white.
Your implication is that white people can't be marginalized. Economics cut across skin color.