I don't think the numbers do reflect that. The percentage of convictions proved to be bad is so miniscule that the difference in which ethnic groups may be overrepresented is little more than a statistical error. It's not a large enough group in total to make any reasonable conclusions.
The "tiny number" of exonerations suggests that the "epidemic of bad convictions" that Scheck suggests is "fiction," said Marquis, chief prosecutor in Clatsop County, Ore. There were 1,051,000 felony convictions in state courts in 2002, up from 829,300 in 1990, according to the federal Bureau of Justice Statistics.
What I do recall from one statistics class I took many many years ago, is that even for a number as large as a million felons, it does not require a large sample to get a reasonable reflection of a representation of the group.
One statistic that would be interesting, is the tens of thousands of suspects identified and pursued, and what the racial make up of those people were. Those statistics will likely not be made available.
I'm going to go out on a limb and present my own perspective. While the media is commonly accused as being "politically correct", we need to keep in mind, this is one group of people, mindset, political slant, etc. There is another group of people in America, that vehemently oppose the perceived "political correctness". And I would say, they have their own set of political correctness and agenda (I'll call it the "other" political correctness). And while most people in law enforcement are honest people trying to do their best, I do believe it is peppered (and quite heavily) with people with this "other" political correctness. And their view of the world is sort of a white counterpart to the African Americans who are determined to see Zimmerman prosecuted.