Updated

If confessed murderer Daryl Keith Holton gets his way, on Tuesday he will become the first prisoner to die in Tennessee's electric chair in 46 years.

Holton, who confessed to murdering his three young sons and his ex-wife's daughter within hours of shooting them to death with a semiautomatic assault rifle, is scheduled to be executed because he quit appealing his death sentence. He also chose the electric chair over the state's preferred method of lethal injection.

Dorinda Carter, spokeswoman for the Tennessee Department of Correction, said even though the state has not used the electric chair to carry out an execution in decades, staff members at the Riverbend Maximum Security Institution in Nashville are trained in using the chair and ready to carry out the execution.

From 1916 until 1960, 125 people were executed by electrocution in Tennessee. In 2000, lethal injection replaced electrocution as the primary method of execution, according to the Department of Correction.

Under Tennessee law, death row inmates can choose between the electric chair and lethal injection if their crimes were committed before 1999.

Stephen Ferrell, Holton's federal public defender, is trying to get the federal courts to stop the execution on the grounds that Holton isn't mentally competent. The 6th U.S. Circuit Court of Appeals is expected to rule Monday on a request for a stay.

Ferrell also is appealing a ruling earlier this month from a federal judge in Knoxville that Holton's case didn't merit a full evidentiary hearing on his competency.

Ferrell says attorney-client privilege forbids him from talking about why Holton chose the electric chair.

Nine states allow some or all condemned inmates to choose between lethal injection and another execution method, according to the Death Penalty Information Center. Ten states have the electric chair but only Nebraska uses it exclusively.

Virginia inmate Brandon Hedrick, 27, chose to die in the electric chair in July, the first execution by that means in more than two years.

The last time the electric chair was used in Tennessee was Nov. 7, 1960, when inmate William Tines was executed for rape. Tennessee did not execute another inmate until Robert Glen Coe by lethal injection in 2000.

John Webster, a professor at the department of biomedical engineering at University of Wisconsin-Madison, says many states have stopped using the electric chair because it's more controversial and gruesome than lethal injection.

"It's disfiguring. The family will end up with the body and frequently find burns on the scalp, leg and neck," Webster said. For witnesses "it's unpleasant to see someone shocked and responding to a shock. The odor and the air smells of burning pork."

On Nov. 30, 1997, Holton told the four children — Steven, 12, Eric, 6, Brent, 10, and their half-sister Kayla, 4 — that they were going Christmas shopping. Nearly five hours later, Holton walked into the Shelbyville Police department and said he had lined up the children at his uncle's auto repair garage and shot them.

Holton, 44, turned himself in after he went looking for his former wife and her boyfriend but couldn't find them. He was found guilty in 1999 of four counts of first-degree murder.

Holton says suffered from severe depression when he committed the murders. His lawyers maintain Holton has a long history of mental illness and may suffer from post traumatic stress disorder from his military service in the 1991 Gulf War.