NASHVILLE (AP) — After four decades with only six executions, Tennessee is on schedule to execute three inmates this year.

Edmund Zagorski died in the electric chair Thursday night after a last minute appeal to the U.S. Supreme Court was declined. His death followed that of Billy Ray Irick's in August. David Earl Miller's execution is scheduled for Dec. 6.

The surge comes as legal challenges to the state's lethal injections protocols have hit a wall, at least temporarily.

"As litigation plays out one state at a time, what we've seen is individual states going on execution sprees," said Robert Dunham. He is the executive director of the Death Penalty Information Center, which does not take a stand on the death penalty but is critical of the way it is applied.

Zagorski, 63, had been on death row for 34 years and seen three execution dates come and go before his Thursday electrocution. Miller, 61, has been on death row 36 years.

At least two things have made executions rare in Tennessee. Stringent legal protections for death penalty cases mean appeals can drag on through years, even decades. But even after the appeals are exhausted, challenges to execution methods have added more delays.

A U.S. Supreme Court 2015 decision made those challenges harder by requiring inmates who object to one method of execution to show there is a readily available alternative that is more humane.

That condition caused a lethal injection challenge by Zagorski and other Tennessee inmates to fail last month. But it hasn't yet had a big effect nationally, where the trend in executions is downward.

According to the Death Penalty Information Center there have been 20 executions so far this year compared to 98 in 1999.

"Everyone says the dam is about to break and there's going to be a surge in executions," Dunham said. "You would think that if lethal injection litigation ends, you might see more executions. That could be the case, but it hasn't happened yet."

One reason is that fewer people are being sentenced to death. Nationally there has been an 85 percent drop in death sentences since the 1990s, Dunham said. Also, several states in recent years have either abolished capital punishment or imposed moratoriums. Washington's Supreme Court struck down the death penalty there just last month.

But national trends could not keep Zagorski from dying in the electric chair.

Kelley Henry, in the federal public defender's office in Nashville, fought for years to keep Zagorski alive. On Thursday night, she served as a witness to his death.

Henry was nodding, smiling and tapping her heart just before the execution. Asked about her actions, Henry said afterward: "I told him when I put my hand over my heart, that was me holding him in my heart."

She said Zagorski told her the last thing he wanted to see was her smiling face, and so she made an effort to smile at him before a shroud was put over his face. Then Henry quietly wiped away tears.

Zagorski was executed for murdering Jimmy Porter and John Dotson in 1983. Prosecutors said he lured the two men into the woods with a promise to sell them marijuana, then shot them, slit their throats and robbed them.

According to his rejected clemency petition, Zagorski reformed in prison, where he never had a single disciplinary infraction and was well liked among the staff.

Henry said the inmate told prison staff before the execution, "I don't want any of you to have this on your conscience. You're doing your jobs and I'm all good."

But Dotson's daughter, Kim Dotson Rochelle, told The Tennessean, Zagorski never apologized to her family, even after he was strapped into the electric chair.

Zagorski's final words were, "Let's rock."

"He had no remorse for what he did. He was smiling just like he was when he was caught," Rochelle wrote in a text message to The Tennessean Thursday night. "That's why he got just what he deserved."