On 22 April 1972, a 58-year-old provisions shop owner who lived in Pulau Ubin, Singapore, was ambushed by two men, who went from the mainland to the island to rob her of her money, cigarettes and gold items. When one of Poon's attackers went into the room to look for valuables, the other attacker, 19-year-old Mohamed Yasin bin Hussin, alias Rosli, took upon himself to rape the victim and in midst of the rape, he caused the elderly victim to die from fatal rib fractures caused by Yasin sitting on top of her to stop her from moving. Both men were eventually arrested nine months after the case and tried for murder.