I Can Prove OJ Innocent: Private Eye Simpson's son killed Nicole Brown, Ron Goldman: PI By Matt Cantor, Newser User Posted Apr 2, 2012 9:20 AM CDT 19 comments Comments OJ Simpson's son did it, says a private investigator. (Getty Images) (Newser) – OJ Simpson wasn't the killer: It was his son who murdered Nicole Brown and Ron Goldman, says a private investigator. Texas PI William Dear has spent 18 years probing the murders, and he explains his case in a new book—and an interview with the Village Voice. Jason Simpson wasn't interviewed by police, nor was his DNA compared to evidence, even though he "had intermittent rage disorder" and was on probation when the slayings occurred. The "Jekyll and Hyde" figure had assaulted an ex-boss with a knife, says Dear, who went so far as to buy a storage unit Jason stopped paying for ... and the PI claims he found a hunting knife inside. On the night of the murders, an angry Jason went to Brown's house after she bailed on plans to dine at the restaurant where he worked, Dear tells the paper. "She probably made a mistake you shouldn't make with people who are off their meds," as Dear says Jason was; she may have slapped him. In a rage, he killed her and an approaching Goldman. As for the blood in OJ's car, it was just a "fingernail"-sized amount, Dear says. OJ headed to the house to check on his kids when he heard from Jason. Realizing he could be a suspect, he panicked, prompting his suspicious behavior. Click through for the Voice's full account of William Dear's story.