Tonight...Hollywood in shock. Rob Reiner, the legendary actor and director, murdered...His wife also found dead. Their son now under arrest. Our time with Rob and the man now accused...His son Nick and his addiction struggles the family spoke about. Plus, Hollywood in mourning...Sharing memories of the man they loved. And, ET honors Reiner whose work is woven into the fabric of American pop culture, on set of his biggest films, and the lines everyone knows. This is Rob Reiner: ET's tribute to a Hollywood icon.