before he left the boat. >> he wrote you might think i am crazy in all this but i think it's worth it to declare geezes to these people. please do not be angry at them or god if i get killed. it's believed he did get killed on his mission trip to the islands. zbls >> reporter: this is one of the oldest and most isolated tribes in the world and they say they're responsible for the killing of john allen chow. this archive footage from survival shows the tribe that live in complete isolation on the tiny island of north sentinel. chow illegally paid fisherman to take him to the isolated island hoping to convert the tribe to christianity.