No, what difference does it make what the cop's "ethnic background" is?
Not from Boston, are you? Don't know anything about Roxbury, I gather?
The odds are it is an ethnic issue. The odds are. Perhaps this is the one in a hundred story where it isn't. But the odds are, it is.
If the party-goers and the suspect shared an ethnic background that differed from the cop's, wouldn't you consider that as making a difference in the situation? Since the races of neither the suspect nor the people beating up on the cop are mentioned, there's no way to tell from this article if that was the case.
The obvious intent of the group was to assist the suspect in getting away. For one reason or another, they aligned themselves with the suspect rather than the cop. Saying anything beyond that is pure speculation without having further details.
Um, you guys, the cop was white. What else would it be?