Japan summoned U.S. Ambassador George Glass. Foreign Minister Toshimitsu Motegi issued a strong protest and demanded U.S. cooperation with the investigation.

On October 4, Okinawa police arrested 20-year-old U.S. Marine Lance Corporal Devin Jacob Ballard, stationed at Futenma Air Station, on suspicion of robbing and murdering 39-year-old Anna Yagi at a hotel in Naha. Japanese police suspect the American soldier killed her and took her wallet and backpack.