Mahdi, 42, was convicted in the 2004 killings of an off-duty police officer in Calhoun County, South Carolina, and a convenience store clerk in Winston-Salem, North Carolina. He was sentenced to death for the murder of the officer and life in prison for the clerk's murder.
Arden's analysis alleged that only two bullets struck Mahdi, both low in the torso and well below the heart, contradicting protocol which requires three shots to the heart for rapid death.
"The shooters missed the intended target area and the evidence indicates that he was struck by only two bullets, not the prescribed three. Consequently, the nature of the internal injuries from the gunshot wounds resulted in a more prolonged death process," Arden said.
The partial damage to Mahdi’s heart allowed continued circulation, leading Arden to determine that Mahdi likely remained conscious for up to 60 seconds after being shot.
Witnesses to the execution, according to The AP, heard Mahdi cry out as the shots were fired, groan again some 45 seconds later and let out one last low moan just before he appeared to draw his final breath at 75 seconds.
Arden also criticized the autopsy for lacking essential documentation, such as x-rays, clothing examination and adequate photographs.
He said that Mahdi's execution failed to meet medical and constitutional standards for a humane death.
In contrast, the autopsy on Brad Sigmon, the first man killed by firing squad in the Palmetto State, showed three distinct bullet wounds and his heart was obliterated, Arden said. He added that the autopsy report in that case included X-rays, adequate photos and a cursory examination of his clothes.
Prison officials have given no indication that there were problems with Mahdi's execution. A shield law keeps many details private, including the training and methods used by the firing squad.
