Clearly there's some confusion here. You said we don't need more representation for bad things, then asked if we should have more white girls with murder cases.

That alone already implies that you think white girls are under represented in the act of murder which would then follow that someone else is who you expect would be more likely to perpetrate that kind of crime.

But then, when asked who is normally showing that 'bad behavior' you explicitly say poor African Americans.

I hope this clears up why some people may have found what you said distasteful and I hope you have a good day.