A woman on death row in the US state of Tennessee remained alive more than an hour after authorities began administering a lethal injection, according to her lawyers.
Christa Pike was scheduled to be executed at Riverbend Maximum Security Institution in Nashville at 10 a.m. local time on September 30.
Her execution was delayed after a last-minute stay, before the US Supreme Court cleared the way for it to proceed several hours later.
Pike’s legal team later filed an emergency petition seeking to halt the execution, alleging that she had been administered two doses of pentobarbital but remained conscious, with a heartbeat and audible breathing.
Witnesses who observed the execution said the process appeared unusually prolonged, with the curtain to the execution chamber being closed several times.
Associated Press journalist Kim Chandler, who was among the witnesses, said Pike appeared to remain awake as the execution began.
She reportedly gasped several times and could be heard snoring loudly after the curtain was closed.
Witnesses were eventually released from the prison, while emergency service teams were seen outside the facility.
Pike’s attorneys said she required immediate medical attention. Prison officials had not publicly confirmed her condition or announced a time of death at the time of the reports.
Pike, now 50, was sentenced to death for the 1995 murder of 19-year-old Colleen Slemmer, a fellow student at a training programme. Pike was 18 when the killing occurred.
Prosecutors said Pike believed Slemmer was trying to take her boyfriend. Pike’s co-defendant, who was also convicted in the killing, was sentenced to life in prison.
Before the scheduled execution, Pike wrote to NBC that she was not afraid to die.
