Christa Pike, convicted of murdering a schoolmate three decades ago, survived Tennessee's effort to execute her by means of lethal injection late on Wednesday, prison officials said, foiling the state's first attempt to put a woman to death in two centuries.
Pike's condition following the ordeal was not immediately made known, and it was not clear after she was taken for medical treatment from the Riverbend Maximum Security Institution in Nashville what legal avenues her lawyers or the state might pursue next.
The Tennessee Department of Correction defended its handling of the high-profile execution, which had been opposed by human rights experts due to Pike's age at the time of the crime, her history as the victim of childhood sexual abuse and untreated mental illness.
"The Tennessee Department of Correction followed every step of the state’s lawful, established execution protocol approved by the Attorney General’s Office," the agency said in a statement.
"The lethal injection chemical in the protocol has consistently been effective, and the protocol does not allow for additional procedures beyond what was carried out this evening. Christa Pike has been transported to an off-site medical facility," the statement concluded.
Pike's lawyers filed a federal court motion during the process seeking to halt her execution, citing witnesses' accounts that "executioners had injected both syringes of lethal injection chemicals and Pike is still alive and snoring," NBC News reported.
The botched execution attempt came hours after the US Supreme Court lifted an 11th-hour lower-court stay of the execution, clearing the way for Pike, 50, to be put to death for her role in the 1995 torture and beating death of 19-year-old Colleen Slemmer in Knoxville. Pike was 18 at the time of the crime.
The Tennessee Department of Correction said after the High Court action that it would "move forward with the execution" later in the day. Procedures to carry out the death sentence began at about 8 p.m. CDT (0100 GMT).
Journalists who witnessed the attempted execution described snoring, loud exhales, gasps and complaints from Pike about pain, as well as her kicking her feet so often that she knocked off the sheets laid on her, according to NBC News. At times, the curtain was closed and journalists could only hear sounds.
"It appeared that this did not go like they thought it was supposed to go,” said John North, investigative producer at WBIR-TV in Knoxville. "But we don’t know that. When we left the building, so far as we knew, she was probably still alive.”
An ambulance was seen arriving at the prison and then leaving.
Tennessee prison officials in May aborted attempts to execute a man convicted of murders after failing to find a suitable vein for a lethal injection.