From 1830 Arthur offered rewards for the capture of Aboriginal people, but bounties were also paid when Aboriginal people were killed. From 1829 efforts were made with the aid of humanitarian George Augustus Robinson to launch a "friendly mission" to persuade Aboriginal people to surrender and be removed to an island sanctuary; from November 1830 to December 1831 several groups accepted his offer[13] and 46 were initially placed on Flinders Island, from which escape was deemed to be impossible.[14] Although conflict between Aboriginal people and settlers almost completely ceased from January 1832, another 148 Aboriginal people were captured in the island's northwest over the next four years as a "clean up" and forcibly removed to Hunter Island and then Flinders Island.[15]