CNN  — 

A Tennessee man who murdered two people in 1984 was executed Thursday, becoming the first inmate in the United States in five years to die in an electric chair.

Edmund Zagorski, 63, had two last words: “Let’s rock.”

Reporter Adam Tamburin, with the Tennessean newspaper, described Zagorski as having a grin on his face at one time, until a sponge and helmet were put over his face. He said Zagorski then grimaced.

Jason Lamb, a reporter with CNN affiliate WTVF, said that Zagorski wore white prison trousers and a yellow shirt. He seemed to wave or raise his left hand as he was prepared for electrocution, including after a black cloth shroud was put over his face, Lamb said.

Relatives of the two men Zagorski killed attended the execution. They chose not to speak to the media.

Zagorski was pronounced dead at 8:26 p.m. ET. His last-day appeal to the US Supreme Court was denied.

Why is the electric chair an option?

Nine states have death by electric chair as an alternative to lethal injection. In 2014, Tennessee became the first state to make use of the electric chair mandatory when lethal injection drugs are unavailable.

By Tennessee law, any person convicted of a capital offense before January 1, 1999 may choose electrocution.

Zagorski began his sentence in March 1984 and the state’s prosecutors had argued “the statute also gives the Tennessee Department of Correction the authority to promulgate rules to carry out the election (of electrocution instead of lethal injection).”

Tennessee has used the electric chair only once since 1960.

Daryl Holton, who killed his three young sons and his ex-wife’s daughter, chose the electric chair in 2007.

Before Holton’s execution, Tennessee had not used the electric chair in 47 years.

The electrocution protocol is practiced monthly by the execution team, and public records indicate the chair was tested in February, the Tennessean newspaper reported.

After Zagorski chose the electric chair, Gov. Bill Haslam issued a reprieve of 10 days to prepare for the execution.

“[T]his brief reprieve will give all involved the time necessary to carry out the sentence in an orderly and careful manner,” the governor said in a statement.

Zagorski’s electrocution was the first in the US since 2013, when Virginia killed a man who murdered two people.

CNN’s Jamiel Lynch contributed to this report.