Umm...how do we know for certain he was murdered specifically because he was black and/or gay and for no other reason? The police said there was no evidence to suggest that. Aren't we kind of making assumptions and jumping to conclusions here without any evidence and before being in posession of all the facts? We really should try to avoid that.
That may well be the reason, but we don't KNOW that for sure. It's speculation. And before anyone says something like "well why else would he have been murdered" that reasoning is a bit too close to God of the Gaps for my taste.