That star witness was also caught lying under oath during the OJ trial, committing perjury. Specifically, he lied about his racism.
Most people that are convinced that OJ did it, believe that based on evidence found by this one police officer. It really comes down to if you believe that a cop that has admitted to planting evidence in the past, is caught lying under oath during this trial, and pleads the 5th rather than saying "I did not plant evidence here again," could have planted evidence.