NASHVILLE, Tenn. — A Tennessee inmate became the second person to die in the state's electric chair in just over a month Thursday, nearly two decades after Tennessee adopted lethal injection as its preferred method of execution.

David Earl Miller, 61, was pronounced dead at 7:25 p.m. at a Nashville maximum-security prison.

Miller was convicted of killing 23-year-old Lee Standifer in 1981 in Knoxville and had been on death row for 36 years, the longest of any inmate in Tennessee.

David Earl Miller Tennessee Department of Correction / via AP

At 7:12 p.m. and after Miller had been strapped into the chair, Tennessee Department of Correction officials raised a blind that had covered the windows to a witness room. Miller looked straight ahead, his eyes seemingly unfocused and his face expressionless.

Warden Tony Mays asked Miller if he had any last words. He spoke but his words were unintelligible. Mays asked him to repeat himself, and his words were still difficult to understand, but his attorney, Stephen Kissinger, said he understood them to be, "Beats being on death row."

Officers then placed a large damp sponge on Miller's shaved head to help conduct the current before strapping a cap to his head. Water ran down Miller's face and was toweled off by an officer. Miller looked down and did not look back up before officers placed a shroud over his face.

After someone connected an electrical cable to the chair, Miller's body stiffened as the first jolt of current hit him. His body then relaxed before a second jolt came less than a minute later. Again, Miller's body stiffened and then relaxed. The blinds were pulled down and an announcement of the time of death came over an intercom.

No witnesses from either Miller's family or Standifer's were present for the execution, but Department of Correction spokeswoman Neysa Taylor read a brief statement from a woman from Ohio who did not want her name given.

Taylor read, "After a long line of victims he has left, it is time to be done. It is time for him to pay for what he has done to Lee."

Miller had been on a date with Standifer, who had mental disabilities, and the two were seen together around town the evening of May 20, 1981. The young woman's body was found beaten and stabbed the next day in the yard of the home where Miller had been living.

Earlier on Thursday, Gov. Bill Haslam refused Miller's request to commute his sentence to life in prison. Miller's petition for clemency said Miller had been physically abused as a child by his stepfather and had been physically and sexually abused by his mother. The petition argued that evidence of the trauma and mental illness it caused should have been presented to a jury.

Assistant Federal Community Defender Kissinger spoke briefly after the execution.

"(Miller) cared deeply for Lee Standifer, and she would be alive today if it weren't for a sadistic stepfather and a mother who violated every trust that a son should have," Kissinger said.

Both Miller and inmate Edmund Zagorski before him chose the electric chair over lethal injection, a process proponents said would be painless and humane.

But the inmates argued in court that Tennessee's current midazolam-based method causes a prolonged and torturous death. They pointed to the August execution of Billy Ray Irick, which took around 20 minutes and during which he coughed and huffed before turning a dark purple.

Their case was thrown out, largely because a judge said they failed to prove a more humane alternative was available. Zagorski was executed Nov. 1.

In recent decades, states have moved away from the electric chair, and no state now uses electrocution as its main execution method, said Robert Dunham. Dunham is the executive director of the Death Penalty Information Center, which doesn't take a stand on the death penalty but is critical of its application.

Georgia and Nebraska courts both have ruled the electric chair unconstitutional, and about two decades ago it looked as though the U.S. Supreme Court would weigh in on the issue. It agreed to hear a case out of Florida after a series of botched executions there. But Florida adopted lethal injection, and the case was dropped.

Dunham said he wasn't aware of any state other than Tennessee where inmates were choosing electrocution over lethal injection.

In Tennessee, inmates whose crimes were committed before 1999 can chose electrocution over lethal injection.

Prior to Zagorski's execution, the builder of Tennessee's electric chair had warned that it could malfunction, but Zagorski's and Miller's executions appeared to be carried out without incident. Miller's death was only the third time Tennessee had put an inmate to death in the electric chair since 1960.

The courts said Miller couldn't challenge the constitutionality of the electric chair because he chose it, even though his attorneys argued the choice was coerced by the threat of something even worse.