That list is actually supposed to show the people they're looking for as far as I can tell (since you can expand the photos for more info and ways to contact the police). If you have a list of most wanted and 90% of them are minorities, what do you do? Do you propose a politically correct list where you can only list an equal number of people of each ethnicity and each gender?
Edit: Also it's worth noting that as of several weeks ago this was a much more elaborate site. It's been significantly toned down since.