Pike, 50, was administered two doses of pentobarbital on Wednesday evening but remained alive. Witnesses reported hearing her breathing and snoring. The execution was halted, the curtain drawn, and Pike was rushed to hospital for "life-saving" medical care.
In a court filing on Friday, Pike's attorneys detailed the events inside the execution chamber. They said prison officials attempted to start intravenous lines using at least seven needles. At one point, Pike herself offered guidance on where they could try. One needle was bent at a 90-degree angle when removed. While receiving the two doses, Pike "could be heard crying, whimpering, and breathing loudly throughout the procedure," according to the filing.
The lawyers alleged that problems with the IV lines caused the pentobarbital to flow into her body instead of her bloodstream. "Apparently at no point did any member of the execution team realise that the IV lines were not correctly placed or that the veins had blown," they wrote. Instead of correcting the problem, they said, the team prepared and administered a backup set of syringes.
Tennessee Governor Bill Lee has ordered an independent review of the state's execution procedures and indefinitely postponed Pike's execution, as well as another scheduled for this year. Other Republican leaders in the state have called for a review of the single-drug lethal injection protocol and consideration of alternative methods.
Pike was sentenced to death in 1996 for the murder of 19-year-old Colleen Slemmer in Knoxville. The attack occurred when both were students at a Job Corps training program. Pike would have been the first woman executed in Tennessee in more than 200 years.
The Tennessee Department of Correction has defended its method, stating that "the protocol does not allow for additional procedures beyond what was carried out." State officials have not provided an explanation of why the dosage proved non-fatal.
Colleen Slemmer's mother, May Martinez, described the events as "a mess," according to NBC News. Pike's attorney Randy Spivey said on Thursday that the prognosis remains unclear.
Medical experts have suggested that Pike may have suffered brain injury due to delays in resuscitation. Professor Joel Zivot of Emory University School of Medicine told the BBC: "It's very possible that as a consequence of the delay of the beginning of resuscitation she will have a brain injury."