I read in the Post that "About 61 percent of the [homicide] cases [in DC] have resulted in an arrest this year." That made me realize that I have no idea whether that's a high number or a low one. So on to Google. Here I learn that in New York City 40.2 percent of murders go unsolved. In 2002, "the clearance rate for murder was 64.0 percent." So DC doesn't seem to be far out of the typical range -- if you kill someone, you've got a bit less than a forty percent chance of getting away with it.