accident but a murder? >> yes, homicide. >> tara has no luft background. she calls herself an intelligence analyst. she and dina have floated several theorys over the years. the current theory? whoever killed max, it was not rebecca zahau. these days, their suspicion is focused on information from a neighbor that's never been verified. the story of a wild party at the mansion the night before max's fall. >> he has not been interviewed by the police and he's not come forward. >> what connection it might have to max's death you have no idea what that is? >> i don't, but i think it should be explored. >> reporter: she said police never spoke with the neighbor, but we did. and he doesn't remember anything about a party. and max's dad, jonah shacknai, who was in the house that night, told us there was no party. jonah says he never doubted the official investigation. but wanted to reput the theorys offered by dina and others.