At the time of his death police said the last confirmed sighting of Mr Roberts had been the day his court appearance was reported but they said they were keeping an open mind about the motive.
On my third day at the camp (and as many days without a sighting) Bakkes and I sat on canvas chairs overlooking a vast plain, our view framed by the Entendeka mountains.
Det Ch Insp Christina Barrett said the last confirmed sighting of Mr Roberts had been on Thursday, the same day it has been reported that he appeared in court.