Georgia's prison system made sound recordings of all 23 executions conducted in the state between 1983 and 1998.
Portions of some of the tapes, which were played on public radio stations Tuesday, are the first documentary evidence of an American execution since a public hanging in Kentucky 65 years ago.
Georgia is believed to be the only state to have taped executions. On the tapes, prison officials provide a dispassionate, minute-by-minute commentary, starting with guards securing the condemned man in the electric chair and ending with doctors declaring him dead.
ABCNEWS' Nightline will play excerpts of two of the tapes tonight: the 1984 executions of Ivon Ray Stanley and Alpha Otis Stephens. Stephens' electrocution had to be repeated because he was still breathing after the first time.
The tapes came to light when they were subpoenaed by Mike Mears, a Georgia criminal defense lawyer, who was challenging the state's use of the electric chair three years ago. They were obtained by documentary radio producer David Isay and broadcast on New York's WNYC and other public radio stations around the country.
Listen to audio files of the executions, or read transcripts.