A Kentucky death row inmate, who pleaded guilty in 1998 of murdering a teenage girl in Caldwell Circuit Court, has had his sentence affirmed in a unanimous decision by the Kentucky Supreme Court issued on Thursday.

Robert Keith Goodall, who is now 50, admitted killing 16-year-old Sarah Hansen in 1997. She had gone to a convenience store to rent a movie, but never returned. Her body was found in a nearby lake and Woodall was charged in her death with kidnapping, murder and rape.

The case has been heard in both the state and federal court systems, with the U.S. Supreme Court upholding the death sentence in 2014.

In the Kentucky Court system, Woodall’s attorneys filed a Motion to vacate the death sentence due to intellectual disability. They argued he is intellectually disabled and, therefore, the imposition of the death penalty would violate his constitutional rights, as the Eighth Amendment to the United States Constitution prohibits imposition of the death penalty on those who are intellectually disabled.

The Kentucky Supreme Court at that time ordered the trial court to conduct a hearing on Woodall’s potential intellectual disability, but after holding a hearing, the judge ruled against Woodall, so the matter came once again before the high court, who heard oral arguments in January.

In their opinion, written by Justice Michelle Keller, the justices held, “Given all of the evidence heard by the trial court, much of which was conflicting, or at least inconsistent, as to Woodall’s deficits, we conclude that the trial court’s factual finding that Woodall did not prove that he is intellectually disabled by a preponderance of the evidence is supported by substantial evidence.”

Woodall remains imprisoned at the Kentucky State Penitentiary in Eddyville, along with the other 25 male inmates on death row. The only woman on death row, Virginia Caudill, is lodged at the Kentucky Correctional Institution for Women, in Pewee Valley.