SIOUX FALLS, S.D. (AP) — A man who pleaded guilty to the 2011 killing of a South Dakota prison guard is set to be executed in the fall, the state's attorney general said Wednesday.

Attorney General Marty Jackley said in a statement that Rodney Berget, 56, is scheduled to be executed between Oct. 28 and Nov. 3. Jackley's office said the warden of the state penitentiary will choose the specific time and date, which will be announced within 48 hours of the execution.

Circuit Court Judge Bradley Zell issued a warrant of execution for Berget, who would be the first person put to death in South Dakota in roughly six years.

"We will be ready to carry out the order of the court," Department of Corrections Secretary Denny Kaemingk said in a statement.

Berget pleaded guilty in April 2012 to killing Ronald "R.J." Johnson in a failed prison escape attempt in April 2011 along with fellow inmate Eric Robert, who was executed in 2012.

An attorney for Berget wasn't immediately available to comment to The Associated Press. Berget's mental status and death penalty eligibility have played a key role in court delays.

Berget in 2016 appealed his death sentence, but later asked to withdraw the appeal against the advice of his lawyers, the Argus Leader reported .

"I want this to be the last day I appear in court," Berget said at a September 2016 hearing.

The last execution in South Dakota was the lethal injection of Donald Moeller on Oct. 30, 2012, for the killing of Becky O'Connell.

State Department of Corrections policy says lethal injections involve one to three drugs, depending on drug availability and the date of the prisoner's conviction. State law makes a drug supplier confidential.

Robert Dunham, executive director of the nonprofit Death Penalty Information Center, said U.S. pharmaceutical manufacturers have distribution policies that prohibit the sale of their medicines for non-therapeutic uses. The "secrecy" provision in South Dakota law raises serious questions about how the drugs are obtained, Dunham said.

"The big problem is that with secrecy we can't have any assurances," Dunham said. "Given the history of behavior of many of the states that have carried out executions, 'Trust me I'm the government,' is not a satisfactory explanation."