I predict this will go away when the victim can't identify which 3, out of the 40+ players, were the attackers. There's no way the DA can prosecute all of them and expect to get any convictions.
When this case first came out, the DA made a statement that he would go forward even if the DNA wasn't positive. Leads me to believe 1) that he thinks he has other evidence and 2) he didn't expect to find DNA.
They should all shave their heads and grow beards.