I agree if it had been a gang of three white youths, and a black youth finishing up dead at the hands of one, it would have been treated much more serious, and if it wasn't there would most likely be some taking to the streets in violent protest.
What is interesting in this case is the fact that the killer's parents, supported their son's alibi even though they knew it to be lies, why have they not been charged with perverting the course of justice?