Stella Walsh was killed during an armed robbery in Cleveland, on 4 December 1980. An autopsy showed that she had no uterus, an abnormal urethra, and a non-functioning, underdeveloped penis, although some sources suggest she also displayed female characteristics. Chromosome analysis revealed that most of her cells contained normal X and Y chromosomes but some were X0 (containing only one X chromosome), resulting in XY gonadal dysgenesis.
The controversy of her biological sex remains unresolved, and the situation is further complicated by the fact that many earlier documents, including her birth record, state that she was female; the Cuyahoga County coroner, Samuel Gerber, stated that Walasiewicz was "socially, culturally and legally" a woman. There has also been controversy over whether her records and achievements should be erased.