In a highly contentious execution, Anthony Boyd, a 54-year-old inmate convicted of a brutal 1993 murder, was put to death using nitrogen gas in Alabama on Thursday. Boyd, who consistently claimed innocence, was sentenced in 1995 for the killing of Gregory Huguley, 32, over a $200 drug debt. The execution took place at 6:33 pm Central time at Atmore state prison, marking the 40th execution in the U.S. this year—the highest number since 2012. Prosecutors alleged that Boyd and three accomplices abducted Huguley at gunpoint, bound him with duct tape, doused him in gasoline, and set him ablaze at a baseball field. Boyd’s conviction relied heavily on the testimony of co-defendant Quintay Cox, who avoided the death penalty. Nitrogen hypoxia, the method used, involves suffocating the prisoner by pumping nitrogen gas into a face mask. This method has drawn sharp criticism from UN experts, who deem it cruel and inhumane. While 23 U.S. states have abolished the death penalty, and three others have moratoriums, President Donald Trump has advocated for its expansion, particularly for severe crimes. Alabama, alongside Texas, has executed five inmates this year, trailing Florida’s 14 executions.