Tennessee death row inmate Christa Gail Pike was taken to a hospital after two doses of pentobarbital failed to kill her during an attempted execution on Wednesday, following a rapidly shifting legal battle that reached the US Supreme Court.
Pike, 50, would have been the first woman executed in Tennessee in more than 200 years and is the only woman on the state's death row.
The Tennessee Department of Correction said it followed the state's established execution protocol but did not immediately explain why the procedure failed.
Earlier Wednesday, the Sixth Circuit Appeals court temporarily halted Pike's execution, saying judges needed more time to consider arguments in her case.
Her lawyers had challenged Tennessee's lethal injection procedures and argued that the method could cause unconstitutional suffering.
The state asked the Supreme Court to lift the stay, and the court overturned it about an hour before the execution deadline, allowing officials to proceed.
Pike had also sought execution by an all-female firing squad, saying she feared lethal injection would be too painful, but that request was denied.
Her lawyers had raised concerns about her small veins and later sought another federal intervention as the execution was underway.
Media witnesses reported that Pike remained visibly alive after receiving two doses of pentobarbital at Riverbend Maximum Security Institution in Nashville.
She was heard snoring and gasping before witnesses were eventually told to leave, while her lawyers said she still had a heartbeat and required immediate medical attention.
Pike was convicted and sentenced to death in 1996 for the 1995 torture and murder of 19-year-old Colleen Slemmer, committed when Pike was 18.
Her former boyfriend, Tadaryl Shipp, who was 17 at the time, received life with the possibility of parole.
Pike's lawyers cited her documented history of childhood sexual abuse, abandonment and neglect in efforts to stop her execution.
Following Wednesday's failed procedure, Tennessee Governor Bill Lee paused the state's remaining 2026 executions and called for a comprehensive third-party review.
Pike's immediate legal and custodial future remains unclear while she receives hospital treatment.