The New York Times has a nice map of homicides in the city. You can select by various variables, but unfortunately not more than one at a time.
The Baltimore Sun has a similar but better map.
I'm always a bit surprised by just how few white homicide victims there are. Or, conversely, how many of the victims are minority. In NYC since 2003 there are about 43 white homicide victims per year out of a population of about 3,700,000. That's a very low homicide rate of 1.16 per 100,000. That's a lower rate than Canada!
Among blacks in NYC, there are about 329 homicide victims a year and 2,240,000 people. That's a homicide rate of 14.7.
Meanwhile in Baltimore, in 2007, there were 14 white homicide victims (a rate of about 7) and 252 black victims (a rate of about 60).
Update: I crunched a few more numbers because, well, I'm curious.
Overall in the U.S. rate is about 5.6 per 100,000. It's about 3.3 for whites and 20 for blacks.
Many other countries have homicide rates under 1. Most civilized countries have rates under 2. We don't even come close. But America has always been a violent place. I guess the real question is why is white New York City so non-homicidal?
And in talking about race and crime, I feel compelled to mention gender and crime. Murder really is a guy thing. In NYC just 8% of murderers (and 17% of victims) are women. And most of those are domestic situations. What is it about men? Can't we all just get along?