Didn't OJ ghostwrote a book where he said "I didn't murder them but if I had here's how I would have done it"?
While in poor taste, the book makes clear why he wasn't the killer:
He had arthritis and wasn't able to maintain strenuous activity. Given Ron Goldman fought a good 15 minutes, he would have gotten trashed.
OJ owned guns.
OJ's Daughter was expecting a friend over for a sleepover and informed him of it, and this friend called off at the last moment. Had he allowed her to testify in both trials, she could also have testified that she heard two unknown male voices and screaming from her mother. OJ and the Goldmans kept her off the stand by agreement to spare her trauma.
Nicole was attempting to get back with OJ only for him to decline due to her drug addictions and he had a girlfriend at the time.
The Mezzaluna Restaurant was a well known drug ring location and everyone on the Jury knew about it. They also knew the police knew about it and did nothing about it. Even when the Rampart Scandal blew up, this was all swept under the rug.
The time scales also don't align either.
There was no way for OJ to have done the murders and thanks to the LAPD, Fuhrman in particular, Vanatter second, and the crime lab third, all evidence leading to the real killers was destroyed.
The Prosecution never had a case and the Civil Case itself should have been thrown out as well.