SYDNEY — Homicide detectives are investigating the death of a 73-year-old grandmother whose body was discovered in a stock dip on a rural property south of Murwillumbah in northern New South Wales, police said. Yvonne Whear, a resident of the NSW Northern Rivers region, had been reported missing in February. Her remains were located in the stock dip — a chemical bath used for treating livestock — on a farm property, according to statements from New South Wales Police.