Here's a story by VoxDotCom, retweeted by Matt Yglesias, and a quick grassroots response.
Of course, you're more likely to be murdered if you live near blacks, do business with blacks, or have black family members. Because of de facto segregation, that applies mostly to blacks.(See Jared Taylor's Paved With Good Intentions, which pointed out that while black crime is well known " It is less well known that blacks are responsible for 73 percent of justified, self- defense killings by civilians, and the overwhelming majority of the people they kill are other blacks.")
It's also the reason for de facto segregation—whites move to "good" neighborhoods because they're not safe in bad ones.
Matt Yglesias lives in a gentrifying part of DC where he's fairly safe. He was randomly attacked on the street by blacks (what we call the "Knockout Game" or "Polar Bear Hunting") but refused to admit that it was a racial attack, and for months refused to describe his attackers as black.
Possibly he hasn't figured out who the killers are in this scenario. As for who is preventing law enforcement, the courts, and executioners from protecting the black victims of black crime, it's it's white liberals like Matt Yglesias.