Man arrested over 1990 SA murder A MAN has been arrested for the murder of a 16-year-old girl last seen more than two decades ago in the South Australian outback. Police said the 42-year-old man was arrested on Thursday in Mount Gambier, was refused bail and will appear in court on Friday. Karen Williams, whose body has never been found, was last seen in the early hours of August 4, 1990, after spending the night with friends at the Opal Inn in Coober Pedy and at a local restaurant. More than 115 statements were taken at the time and police enquiries extended to the Northern Territory and New South Wales. Police acted on new information in July and excavated a series of old mines at Coober Pedy in renewed efforts to find her remains. Detectives have since interviewed people from Sydney, Adelaide, Mt Gambier and Coober Pedy, and major crime boss detective superintendent Des Bray said they received valuable information that had progressed the investigation. "We believe Karen's body was left in the boot of a burnt-out white Ford on the edge of town," Supt Bray said in August. Information is leading us to believe that Karen's body was removed from this car and placed down a mine shaft about 20 metres away. A $200,000 reward was offered last year for information leading to an arrest in the case. Police said on Thursday they will be returning to the town within weeks to recommence the search for Ms Williams' remains.