I've seen the Peter Bergman film, it's fascinating. There's CCTV of him with a purple carrier bag that is full when he leaves the hotel and empty when he returns and no one knows why.
It looks like he went to the beach and undressed in order to drown himself but he actually died of a heart attack. How could he plan that?
And no one knows who he is - not a single friend, acquaintance, neighbour, co-worker, ever came forward. He even bought postage stamps in Ireland so he must have contacted someone.
How can anyone be so completely anonymous?