An inmate on South Carolina's death row seeks to postpone his execution, alleging that his co-defendant lied about not having a plea deal.

An inmate on South Carolina's death row, set to be executed this month, is requesting the state Supreme Court to postpone his execution so his attorneys can present evidence that his co-defendant who testified against him lied about having a plea deal in exchange for his testimony.

On September 20, Freddie Eugene Owens, 46, will be executed for the 1997 murder of store clerk Irene Graves during a series of robberies in Greenville. Owens also killed his cellmate at the Greenville County Jail in 1999, before his sentencing.

The Associated Press reported that attorneys for Owens filed court papers on Friday stating that a juror noticed an electronic stun device Owens wore in court to maintain good behavior, and that the judge did not explain why he was required to wear it.

South Carolina is seeking to execute Owens, marking the state's first execution in 13 years after a pause due to difficulties in obtaining lethal injection drugs.

The state's lawyers have until Thursday to respond to Owens' request for a delay in his execution and present new evidence to a judge in order to request a new trial.

New evidence emerged only as Owens' potential execution neared, despite previous attorneys carefully scrutinizing his case.

Steven Golden, a co-defendant, testified that Owens shot Graves in the head due to her inability to open the safe at the Greenville store 27 years ago.

Despite having surveillance video, the shooting was not clearly visible. Prosecutors were unable to locate the weapon used in the shooting and failed to present any scientific evidence linking Owens to the murder.

In 1999, at his trial, Golden stated that he did not have a plea agreement with prosecutors and was still at risk of receiving a death or life sentence after testifying.

In a sworn statement signed Aug. 22, Golden admitted to reaching a side deal with prosecutors, which Owens' attorneys claimed might have influenced jurors' beliefs about his testimony.

"My written plea agreement stated that the death penalty and life without parole were still possible outcomes, and there were no specific assurances regarding my sentence," Golden stated. "However, we had a verbal agreement that I would not receive the death penalty or life without parole."

Court records indicate that Golden was given 28 years in prison after pleading guilty to voluntary manslaughter.

Owens' lawyers argued that courts must explain to juries why defendants wear visible restraints, such as shackles, and that judges must balance courtroom security with the potential impact of the device on a fair trial.

Owens' lawyers said the judge failed to do this in his trial.

Since 2011, South Carolina has not executed anyone due to difficulties in obtaining lethal injection drugs after their supply expired because of pharmaceutical companies' concerns about disclosing their sales to state officials. However, the state legislature passed a law last year that protects the identity of lethal injection drug suppliers.

South Carolina has changed its lethal injection protocol to use only one drug, the sedative pentobarbital, similar to the federal government's method.

Owens will have lethal injection, electrocution, and a firing squad as execution options until Sept. 6. He has delegated the decision to his lawyer, Emily Paavola, through a signed power of attorney.

The South Carolina Supreme Court will decide if Owens' lawyer can make the decision for him regarding his sentencing to the electric chair.

Mr. Owens believes that physically signing the election form is equivalent to suicide and goes against his deeply held religious conviction, as his Muslim faith prohibits suicide.

The state Supreme Court has decided to postpone executions for at least five weeks.

The court rejected a request from lawyers for the condemned inmates to delay executions by three months to ease pressure on prison staff and allow lawyers to focus solely on each prisoner's case.

The court could issue execution orders every week on Friday under state law and a timeline first issued when the justices ruled executions could restart last month. Prison officials told the state that four weeks would be acceptable.

South Carolina currently has 32 inmates on death row.

The Associated Press contributed to this report.