The video itself is quite disturbing as you hear people laughing and enjoying the scene of carnage. It is also worth noting that there are some who can be heard expressing concern and the need for an ambulance.
It is not clear if there was a racial component to the crime and I would not immediately expect a hate crime investigation in such a case. Various blogs however are arguing that the Administration and local officials often immediately pledge to pursue such cases involving a black victim and white officers or assailants as a possible hate crime. I have tended to caution that such early framing of cases can have a distortive or dysfunctional impact absent clear evidence of a racial motivation. For example, while some in this crowd may have been celebrating the fact that the victim was white, it does not mean that the original attack was racially motivated.