Physicians noticed Aldrich-Mees' lines on Carol's nails. Forensic tests on samples of her hair were conducted by the Alabama Department of Forensic Sciences on October 3, 1979, revealing arsenic levels ranging from over 100 times the normal level close to the scalp to zero times the normal level at the end of the hair shaft. This indicated that Carol had been given increasingly larger doses of arsenic over a period of four to eight months. That same day, Frank Hilley's body was exhumed, and upon examination, showed between 10 times and 100 times the normal level of arsenic. It was concluded that both Frank and Carol had suffered from chronic arsenic poisoning, with Frank's poisoning being fatal.
