A convicted murderer has been executed by a firing squad in Utah after a flurry of last-minute bids for mercy were rejected, authorities said.
Ronnie Lee Gardner, 49, was shot through the heart by a five-man team of sharpshooters at approximately 12.20 local time (0620 GMT), a spokesman for the Department of Corrections told reporters.
"The execution warrant was served at approximately 12.20 and 25 seconds," department of corrections spokesman Steve Gehrke said.
In a bizarre twist, Utah Attorney General Mark Shurtleff announced on micro-blogging site Twitter he had given the final approval for the execution.
"I just gave the go-ahead to Corrections Department to proceed with Gardner's execution," Shurtleff tweeted shortly before Gardner was shot. "May God grant him the mercy he denied his victims."
Gardner was the first death row inmate to be executed by firing squad in the United States since 1996.
Execution by firing squad was outlawed by Utah in 2004 but the ban was not retroactive, allowing Gardner to choose the gruesome method instead of lethal injection during a hearing in April.
Gardner had spent 25 years on death row for gunning down an attorney in a failed bid to escape from a court room in 1985 during a murder trial.
Gardner's case had renewed debate about use of the death penalty in the United States and divided family and friends of his victims.
Loved ones of lawyer Michael Burdell, shot dead by Gardner in his botched escape attempt, have said they were against his execution because Burdell opposed the death penalty.
