Didn't ask, but a possible answer: personality change due to head trauma (much less well understood then).

Also Important to my mind: O.J. did beat and abuse Nicole but with his hands (fists). Obviously, no excuse. But he never used a knife or other weapon, while the suspect Dear names was on probationthat night for a knife attack against a former girlfriend. The overlooked suspect's profile just seems to fit the crime better than O.J.'s does.