The victim is black, it's a big jerk - fest for the liberal media, a cause celebre.
no, its because it was so obviously a screwed up investigation by an incompetent and institutionaly racist police force as it was at the time coupled with new DNA matching techniques that weren't available at the time.
It's righting a wrong from a long time ago, chances are they would have been out by now had they been convicted at the time, as it goes they've probably had a crappy life in the meantime and now they'll get to go down for life in for the bargain.
Good riddance, even if you insist on the evidence being unsafe (although the whole contamination thing was investigated in depth, presented to the court and they allowed the evidence) they are at the very least violent, criminal, racist scum (who've gone on to collect several other convictions along with dodgy aquittals for stabbings/assaults etc) so I'm quite happy they're in prison.
Now to get the others!