The US state of Ohio on Thursday put to death a convicted killer via lethal injection, authorities said, sparking controversy 
over the use of an untested method after supplies of the drug previously used dried up.
Dennis McGuire, 53, who was sentenced to death for the 1989 rape and murder of a pregnant woman, was pronounced dead at 10:53 am in Lucasville, a spokeswoman for the Ohio prisons authority said.
The state had said that it would employ the sedative midazolam and the painkiller hydromorphone — a drug cocktail never before used in a US execution.
An official confirmed the use of the mixture to CNN.
Ohio, like many US states, faced a shortage of the anesthetic formerly used in executions after European manufacturers refused to provide the substance for use in carrying out the death penalty.
McGuire’s lawyers said he would die of asphyxia in a phenomenon known as “air hunger,” inflicting the sort of “cruel and unusual punishment” prohibited under the US Constitution.
But appeals, which went all the way to the US Supreme Court, were rejected. A federal judge in Ohio, Gregory Frost, said that “the evidence before the court failed to present a substantial risk that McGuire will experience severe pain,” according to a court document.
Phillips was supposed to be the first man to die under the new procedure, but his execution was rescheduled for July, to consider his request to donate his organs.
McGuire is the third man to be executed in the United States this year.
Ohio executed three of the 39 people put to death in the United States last year, according to the Death Penalty Information Center.