NASHVILLE, Tenn. (AP) — Tennessee officials must deactivate a death-row inmate ‘s implanted heart-regulating device to avert the risk that it might try to shock him during his lethal injection, a judge ruled Friday.

The order by Nashville Chancellor Russell Perkins comes ahead of the Aug. 5 execution of Byron Black. Black’s attorneys have said that the implantable cardioverter-defibrillator could shock him in an attempt to restore his heart’s normal rhythm after the single dose of pentobarbital, with the potential for multiple rounds of shocks and extreme pain and suffering.

The order requires the state to deactivate the device moments before administering the lethal injection, including having medical or certified technician professionals, plus equipment, on hand. The lower-court judge said the order will not serve to delay the execution, something he said he does not have the authority to do. He also said it doesn’t add an undue administrative or logistical burden for the state.

Black’s attorneys say the only surefire way to shut off the device is for a doctor to place a programming device over the implant site, sending it a deactivation command. It is unclear how quickly the state could find a medical professional willing to do the deactivation. Additionally, the state is almost certain to file a quick appeal.

The implantable cardioverter-defibrillator is a small, battery-powered electronic instrument that is surgically implanted in someone’s chest, usually near the left collarbone. Black’s was inserted in May 2024. It serves as a pacemaker and an emergency defibrillator. At a two-day hearing this week, experts offered clashing testimony on how it would act during the execution and what Black could feel if he is shocked.

Attorneys for the state deemed it highly unlikely that the pentobarbital would trigger the device’s defibrillating function, and if it did, they say he would be unconscious and unaware, and unable to perceive pain. The state also said the lower-court judge lacked authority to order the device disabled.

Black’s attorneys say the state is relying on studies that confuse unawareness with unresponsiveness. The inmate’s team says research shows pentobarbital renders people unresponsive and causes them to experience amnesia after they undergo an operation, but it doesn’t make them unaware or unable to feel pain..

Kelley Henry, an attorney for Black, said she is relieved by the ruling.

“It’s horrifying to think about this frail old man being shocked over and over as the device attempts to restore his heart’s rhythm even as the State works to kill him,” Henry said in a statement. “Today’s ruling averts that torturous outcome.”

A Tennessee attorney general’s office spokesperson did not immediately respond to requests for comment Friday evening. Its previous filings say Black is trying to further delay justice for brutal murders.

Black was convicted in the 1988 shooting deaths of girlfriend Angela Clay, 29, and her two daughters, Latoya, 9, and Lakeisha, 6. Prosecutors said Black was in a jealous rage when he shot the three at their home. At the time, Black was on work-release while serving time for shooting and wounding Clay’s estranged husband.

Black has already seen three execution dates come and go, thanks to the COVID-19 pandemic and a pause on executions from Gov. Bill Lee after the Department of Correction was found to not be testing the execution drugs for potency and purity as required. Black’s execution would be the second one under a pentobarbital protocol released in December.

Black is intellectually disabled, attorneys say

Black’s attorneys have previously tried and failed to show that he should not be executed because he is intellectually disabled, and that would violate the state’s Constitution.

The state Supreme Court recently declined to order a hearing over whether he is incompetent to be executed. A U.S. Supreme Court effort remains pending.

Black’s legal team has filed a request for the governor to commute his sentence to life in prison. The letter asking for clemency says Black suffered from prenatal alcohol exposure and exposure to toxic lead as a toddler, compounding lifelong cognitive and developmental impairments.

The 69-year-old is now in a wheelchair, suffering from dementia, brain damage, kidney failure, congestive heart failure and other conditions, the clemency letter says.

Additionally, the clemency request says if he had delayed filing his intellectual disability claim, he would have been spared under a 2021 state law.

Black’s motion related to his heart device came within a general challenge he and other death row inmates filed against the state’s new execution protocol. The trial isn’t until 2026.