welcome back to "dateline" i'm natalie morales. after leading los angeles police on a meandering car chase, o.j. simpson announced he was heading to his tony estate in brentwood. the suspect in a double murder, simpson was armed and officers believed dangerous. soon the drama would take a surprising turn, putting more lives at risk. once again, here's josh mankiewicz with "chasing o.j. simpson" the untold stories. >> the race to rockingham was on. a s.w.a.t. team convoy versus a ford bronco carrying al cowlings and o.j. simpson just minutes apart. >> information, advising not to close in on the vehicle. >> most of us who think we know the simpson story believe that what happened after that surreal