A number of people - Chris of Qwghlm here, for example - have pointed out that whilst Ian Blair may not have chosen the best case with which to make his point about levels of crime reporting reflecting the race of the victim, that doesn't prevent him from being on to something. As Chris points out, there are other factors apart from race that work to determine media interest in the victims of crime: their level of general innocence, as callibrated from a combination of their age, their gender, and the degree to which they fulfill expectations of the role which the Daily Mail assigns to them on the basis of those two variables, is the obvious one, but attractiveness and pertinence to readers also plays a role.
I, for example, have often thought that the middle market tabloid campaigning on behalf of Stephen Lawrence's family was motivated by the fact that both the victim and the family conformed to all the desires that such publications could have about anyone and how they lived their lives. It was as if they'd suddenly discovered that being black didn't automatically push you into the category of lumpenproletariat. The Lawrence family managed to escape the usual stereotypes by virtue of being quite respectable, so far as I can remember, and having a son who had the appropriately high-minded but ultimately bland and unthreatening ambition of becoming an architect. I thought at the time that this showed that actually, rather than race being the relevant causative factor in the injustice, class was: being black was a marker for being a member of the non-respectable working class. I'm fairly sure that it's not that simple now - there are tropes to do with the aggressiveness of young black men particularly which are distinct from more general class prejudice, for example - but I think it is worth thinking about how closely race and class are related. I remember there was a case of a bishop who was stopped for driving whilst black, fairly soon after the whole Lawrence thing broke, which was regarded as scandalous. What was scandalous about it was that it was a bishop who got stopped for driving whilst black, though, not that someone whom the police had no basis for suspecting of a crime other than the colour of his skin was stopped at all. His position and what that implied about his class took him out of the category of being black.