Tennessee’s governor on Monday ordered a halt to all executions until the end of the year and opened an investigation into why the state had failed to properly test lethal injection drugs to be used on a prisoner last month.
The execution of the prisoner, Oscar F. Smith, was halted about an hour before he was scheduled to be killed because the drugs were not tested for endotoxins, pollutants that could cause unpredictable side effects if injected. The moratorium will temporarily delay the execution of Mr. Smith and four other men who were scheduled to die this year.
The lack of testing for the toxins, which experts said could cause respiratory failure or other unpleasant symptoms before death, was the latest in a series of failures and challenges for states seeking to carry out the death penalty, as they find it more difficult to obtain lethal drugs. A judge in Oklahoma is currently weighing whether a drug used during executions in several states, including Oklahoma and Tennessee, is constitutional, and South Carolina is preparing to carry out its first execution by firing after saying it could no longer acquire lethal injection medication.
Tennessee Gov. Bill Lee, a Republican, said Monday that Ed Stanton, a former federal prosecutor in Tennessee, would lead an investigation into why the drugs used for lethal injection were not tested for the endotoxins.
Mr. Smith’s lawyers, who had called for a moratorium and investigation, welcomed the governor’s move.
“The use of compound drugs in lethal injection is fraught with risk,” Kelley Henry, the top death penalty lawyer at the Federal Public Defender’s Office in Nashville, said in a statement. “The lack of testing for endotoxins is a violation of the protocol. Governor Lee did the right thing by stopping executions because of this breach.”
Dr. Harry Kochat, an expert in pharmaceutical science at the University of Tennessee Health Science Center, said endotoxins are left behind when bacteria are killed and can quickly cause hypertension, respiratory failure and other catastrophic effects, depending on the dose.
“The moment the endotoxins come in, the first symptom that is often reported is fever, and it can cause secondary infections and affect your organs,” said Dr. Kochat.