The fact is, there a ton of little things that go into a judge's decision/ruling and you couldn't possibly hope to ever find a simple apples to apples comparison between them.
For example, here's two cases of assaulting a minor...
Woman accused of assaulting minor
Three Sisters Accused of Assaulting a 12-Year-Old Girl – City of Columbia Police Department
Let's imagine for a moment that they happened in the same place...went before the same judge...that they faced the same assault charges (and nothing else)...and they had the exact same criminal history, none. I'd bet dollars to cents the three black girls get a "harsher" sentence...and it wouldn't have anything to do with race, just the details of their crime. Three sisters going to a twelve year old girl's house and beating her isn't the same as a mother stepping between her daughter and another child who are fighting and beating the other child. That's exactly why we let judges impose sentences based on their subjective experience.