The State Board of Pardons and Paroles denied clemency late Wednesday for Carlton Gary, who has been on death row for 32 years following his conviction for three 1970s murders in Columbus that prosecutors attributed to “the stocking strangler.”

The board's order leaves the execution scheduled for 7 p.m. Thursday at the Georgia Diagnostic and Classification Prison in Jackson.

Gary's attorneys, Jack Martin and Michael McIntyre, made a plea for clemency, arguing that DNA evidence and other developments after the 1986 trial brought the convictions into question. The board declassified a 30-page motion for clemency detailing the assertion that Gary could not be the stocking strangler.

The case was one of the most notorious in the state's history, terrifying a city as elderly women were raped and murdered in their homes and left with their own stockings tied around their necks.

Gary is scheduled to die by lethal injection for the 1977 rapes and murders of Florence Scheible, 89, Martha Thurmond, 70, and Kathleen Woodruff, 74. Prosecutors linked Gary to the string of nine similar murders in Columbus—plus others earlier in the New York cities of Albany and Syracuse.

The parole board met Wednesday to receive information for or against clemency and announced its members have been reviewing the parole case file on Gary for the past several weeks. The announcement of the denial of clemency said the board maintains a comprehensive file on each death row inmate. The file contains the history of the life of the condemned inmate, including the inmate's criminal history and the circumstances of the crimes committed, resulting in the death sentence. In Georgia, the parole board has the sole constitutional authority to grant clemency in a death penalty case.