Authorities in Okmulgee County are continuing to search for a woman whose boyfriend says he killed following an argument.Ashley Celeste Taylor of Okmulgee was last seen by her family on July 15th. Police arrested Kevin Sweat Thursday on a complaint of first-degree murder in Taylor's death.Sweat was interviewed by investigators last week. They say he told them he and Ashley had left Okmulgee and were heading to Louisiana to marry. But, he said they got into an argument and that he had let her out of the car on Highway 75 between Schulter and Okmulgee.Wednesday, investigators say Sweat changed his story and confessed to killing Ashley. He told investigators where they were at the time of her death and officers have been searching that location for her body.Okmulgee Police Chief Joe Prentice told NewsChannel 8 Friday that they are still looking for Taylor. He says Okmulgee County Sheriff's Office, Okmulgee Police, Henryetta Police, Creek Nation Police and agents from the Oklahoma State Bureau of Investigation are helping in the search.