SIOUX FALLS, S.D. (AP) – A woman in her 80s who was suspected but never charged in the 1975 killing of a fellow American Indian Movement activist has died at a nursing home in western Nebraska. Michael Selzler of Sioux Funeral Home in Pine Ridge says Theda Clarke died Saturday and arrangements were being made. Clarke, according to court records, had been suffering from the effects of a stroke, dementia, diabetes and other ailments. Her exact age could not be confirmed. In December, she was ruled competent to testify in the murder trial of John Graham but exercised her Fifth Amendment right not to incriminate herself. Clarke graduated from St. Francis Indian School and began a nursing career at St. Mary’s School for Nursing in Kansas City, later working on the Pine Ridge Indian Reservation.