Actually, it is more "hard evidence" than an account by someone years later. Memory is a fickle thing than can very easily be tainted, changed, or even created out of nothing. Unless the account was documented at the time, it doesn't carry much weight now. A specific report, made at the time, on the other hand, is specific and hasn't been changed over time. It is what it was then. That doesn't prove it was true or accurate, but it's certainly more credible than an account based on memories from a decade ago -- especially considering the tremendous motivation (depending on which "side" the witness is) to either discredit or support King's account in light of current reality.
Dang it, I have to agree with you on this. There is the distinct possibility that his biological father is not the guy listed on the birth certificate. I also think it's highly likely that he's been embellishing on his stories of vicimization to gain more influence as a SJW, which would easily explain the differences between police report of the incident versus his account.
Well, which explanation that fits all the information provided is simpler? Him lying to gain scholarships and lying/embellishing on his stories as a victim to gain credibility the movement seems a lot more simple than the birth certificate being wrong, plus relatives saying he's white being wrong, plus the police lying on the report created at the time etc.
I have to admit there is at least the possibility that he's telling the truth regarding his father (even if his claims of attacks etc are false).
At this point, since his mother's reputation has already been dragged through the mud (by King himself btw), what's the harm in taking the DNA test to prove things one way or the other?