Child killer becomes first to be executed with defibrillator fitted

A triple-killer has become the first man to be executed with a working defibrillator implanted in his chest Byron Black, 69, was put to death in Tennessee without the defibrillator being deactivated.

There were concerns the device would shock his heart when the lethal chemicals took effect. A bid to delay the execution was denied on Monday.

Black died at 10.43am, prison officials said, about 10 minutes after the process began. Seven media witnesses said he appeared to be in discomfort.

He looked around the room as the execution began and could be heard sighing and breathing heavily, the AP news agency reported. The Death Penalty Information Center, which provides data on such matters, said it was unaware of any similar cases.

Black's attorneys said they had not found a comparable case either. Black shot dead his girlfriend Angela Clay and her two daughters, aged six and nine, in a jealous rage in 1988.

He committed the murders while on work release while serving time for shooting Clay's estranged husband. Linette Bell, whose sister and two nieces were killed, recently told local station WKRN-TV: "He didn't have mercy on them, so why should we have mercy on him?" There was uncertainty over whether the defibrillator would shock his heart, potentially prolonging his death and causing suffering.

The 69-year-old was in a wheelchair and said to have dementia, kidney failure, brain damage and congestive heart failure. His cardioverter-defibrillator was a battery-powered device that delivered electric shocks to restore a regular heartbeat if needed.

Black's lawyers said a doctor should have put a device over the implant to ensure it was switched off. In July, a judge agreed it was necessary to avert the chance of unnecessary pain.

Last week, however, the state Supreme Court said the judge lacked authority to order the defibrillator to be deactivated. Lawyers representing Tennessee argued the lethal injection would not cause the device to shock Black and that he would not feel it even if it did.

However, his lawyer, Kelley Henry, said the execution could become a "grotesque spectacle" and Black could still be in pain even if he looked unresponsive. Read more:Execution of man who killed wife and kids sets new recordMan on Death Row for almost 50 years executed Black's lawyers also tried unsuccessfully in recent years to save him from execution by arguing he was intellectually disabled and ineligible for the death penalty under US Supreme Court precedent.

Twenty-eight men have been executed in the US so far this year - the highest since the 28 also killed in 2015. Nine other executions are scheduled before the end of 2025..