Inmates in Florida, Georgia, and Missouri are scheduled to be killed by lethal injection in the next 24 hours.
The executions are the first in seven weeks following the botched lethal injection of an Oklahoma prisoner.
The Oklahoma Department of Corrections bungled one execution and stopped another on April 29 after a new drug in the lethal injection cocktail failed to render Clayton Lockett unconscious.
Lockett began convulsing after the first drug, midazolam, was injected, and died 43 minutes later of a heart attack. The second inmate, Charles Warner, received a six month stay of execution.
States across the country have had to change their cocktails after several European drug manufacturers banned American prisons from using their products in executions. The states executing prisoners this week have refused to say what drugs they are using or if the products have been tested.
Marcus Wellons, convicted of raping and murdering a 15-year-old in 1989, will face execution in Georgia. At 12:01 a.m. Wednesday in Missouri, John Winfield is scheduled to die. Winfield shot his ex-girlfriend and two of her friends in 1996. The friends died, and the ex-girlfriend was blinded.
John Ruthell Henry will face execution in Florida at 6 p.m. on Wednesday. Henry was on parole for a 1976 murder when he killed his estranged wife and her son in 1985. His IQ is 78—eight points too high to be considered mentally disabled in the state.
After the failed Oklahoma execution, both attorneys for the prisoners and the Oklahoma ACLU legal director criticized and called for increased transparency in lethal injection procedures. Death penalty expert and Fordham University School of Law professor Deborah Denno said that the next 24 hours will be studied by lethal injection opponents and advocates.
"I think after Clayton Lockett's execution everyone is going to be watching very closely," she told the Associated Press. "The scrutiny is going to be even closer."