Tennessee halts executions after Christa Pike survives two lethal injections

Christa Pike, 50, survived two attempts to execute her by lethal injection in the US state of Tennessee on 30 September, according to the BBC. Her lawyers said she woke up and began speaking from her hospital bed almost a week after the execution attempt. She was convicted of the 1995 murder of 19-year-old Colleen Slemmer, whom she met at a summer camp for troubled teens. According to the BBC, Slemmer was killed by Pike and Pike's then-boyfriend.

Tennessee Governor Bill Lee ordered an independent review of what went wrong in the Nashville execution chamber on 30 September, and halted executions in the state for the rest of the year. The Tennessee Department of Correction is yet to say why the execution did not go as planned. It has defended the method it used, saying "the protocol does not allow for additional procedures beyond what was carried out".

Dr Joel Zivot, an anaesthesiologist advising Pike's defence team, said it was not the case that Pike had some "special immunity"; he suggested not enough of the drug pentobarbital reached her bloodstream to kill her. He told the BBC that most of the pentobarbital "ended up in her arms" rather than circulating in her body. Pike was injected with a second dose of the drug after the first did not kill her, according to the prison authorities' protocol.

Pike's legal team highlighted her thrombocytosis, a blood-clotting condition, in advance as an issue that could affect the process, and filed a legal case challenging the injection protocol. The lawyers said clots of blood forming at the injection site could potentially have blocked the chemical from entering her veins. Prison officials used at least seven needles on Pike to establish intravenous lines, her lawyers said, and she could be heard "crying, whimpering, and breathing loudly".

May Martinez, the mother of Colleen Slemmer, told NBC the failed execution had been "a mess". The state protocol does not clearly specify what should happen if an inmate remains alive after a second dose, according to the AP news agency. After it became clear Pike was not going to die from the two doses, she was taken to hospital for life-saving treatment; states have a legal obligation not to deny medical treatment to prisoners.

Pentobarbital is a potent sedative that slows down the body, including the nervous system, according to the BBC. Doctors sometimes use it as a treatment for certain conditions, but in high doses it can also be used as a lethal injection to cause death.