By the way, Mullis never testified at OJ's trial. Yes, his PCR technique was used, but the primary flaws in the DNA technology were the fault of the FBI and the LA police who almost certainly falsified evidence. I don't see how you can accuse Mullis of having any significant impact on the outcome.
IIRC, he got the idea while high on LSD, causing scores of acidhead burnouts to rant "SEE?!?!?! SEE?!?!?!"