A judge on Tuesday dismissed a motion to declare a Tennessee death row inmate intellectually disabled, a move that would have prohibited his upcoming execution.

Senior Judge Walter Kurtz wrote that federal courts had previously determined Byron Black was not intellectually disabled and therefore was ineligible to have the decision considered once again. The 45-page decision comes despite agreement between Nashville’s district attorney and Black’s lawyers that he is intellectually disabled and should not be put to death.

Black is scheduled to be executed on Aug. 18 for his murder convictions in the April 1988 killings of his girlfriend and her two young daughters.

Black’s attorneys had argued the 65-year-old should be spared under a 2021 law that made Tennessee’s prohibition against executing people with intellectual disability retroactive, pointing out there is a different standard in place now than in 2004 — when the court found that Black didn’t meet the now-obsolete definition of “mental retardation.” Previously, Tennessee had no mechanism for an inmate to reopen a case to press an intellectual disability claim.

However, Kurtz ultimately concluded that the new state law does not apply to death row inmates who had previously received a ruling from a prior court.

“This Court fails to see how the federal courts’ resolution of petitioner’s intellectual disability claim can be seen as anything other than an adjudication on the merits under the legal and medical principles which are embodied in the most recent version of (Tennessee law),”Kurtz wrote. “Given the above, the Court finds that Mr. Black had a full and fair previous adjudication on the merits of his intellectual disability claim.”

Black was convicted by a Nashville court in the deaths of girlfriend Angela Clay, 29, and her daughters Latoya, 9, and Lakesha, 6. Prosecutors said he was in a jealous rage when he shot the three at their home. At the time, Black was on work release while serving time for shooting and wounding Clay’s estranged husband.

Earlier this month, District Attorney Glenn Funk — Nashville’s lead prosecutor — announced that he agreed with Black’s legal team that the inmate was intellectually disabled and should instead face a sentence of life in prison.