WASHINGTON: Defense Secretary Ash Carter spoke by phone Saturday with his Japanese counterpart after an American who works on a US air base in Okinawa was arrested for his links to the death of a local woman. In the call to Gen Nakatani, Carter “conveyed his sadness and his regret” over the murder of the young woman “and extended his sincere apologies to the victim’s family and friends,” the Pentagon said in a statement. Okinawan police arrested Kenneth Franklin Shinzato on Thursday for allegedly disposing of the woman’s body in a weed-covered area in southern Okinawa. Shinzato, a US citizen and former US Marine who works at the Kadena Air Base, has reportedly admitted to raping and killing 20-year-old Rina Shimabukuro, who had been missing since late April. Nakatani on Saturday traveled to Okinawa to lodge a formal protest with the US base commander.