The state had planned to put eight men to death before its supply of the sedative midazolam expires on Sunday, the AP reported. Courts issued stays for four of the men who were scheduled to die.
Witnesses in the chamber, including an Associated Press reporter, said Williams lurched 20 times on the gurney before three lethal drugs took his life. The movements were described as “lurching, convulsing, coughing and jerking.”
Shawn Nolan, one of Williams' attorneys, said in a statement that he is requesting "a full investigation into tonight's problematic execution."
A spokesman for Arkansas Gov. Asa Hutchinson told the AP that Williams’ movements were an "involuntary muscular reaction" to one of the drugs used.
Spokesman J.R. Davis said he expects Hutchinson to review the execution.