McALESTER, Okla. (AP) — Oklahoma executed inmate Benjamin Cole on Thursday morning despite claims from his attorneys that he had been severely mentally ill.

Cole was pronounced dead at 10:22 a.m. at Oklahoma’s state penitentiary in McAlester. He was the sixth Oklahoma inmate to be executed since the state resumed carrying them out in October 2021.

Attorneys for Cole did not dispute that he killed his infant daughter, 9-month-old Brianna Cole, by forcibly bending her backward, breaking her spine, and tearing her aorta. But they argued that Cole was severely mentally ill and that he had a growing lesion on his brain that had worsened in recent years.

Cole refused medical attention and ignored his personal hygiene, hoarding food and living in a darkened cell with little to no communication with staff or fellow prisoners, his attorneys told the state’s Pardon and Parole Board last month during a clemency hearing.

“His condition has continued to decline over the course of this year,” Cole’s attorney Katrina Conrad-Legler said.

The panel voted 4-1 to deny clemency, and a district judge earlier this month determined Cole was competent to be executed. Two last-minute appeals filed with the U.S. Supreme Court seeking to halt his execution were rejected, one on Wednesday and another Thursday morning.

In a separate case Wednesday, a federal appeals court panel upheld a lower court’s ruling earlier this year deeming Oklahoma’s execution protocol constitutional. Cole was among more than two dozen death row inmates who filed suit, citing, among other things, a series of problems in the death chamber, including a botched execution in 2014.

“Oklahoma’s earlier problems in the execution chamber are not enough to show that future similar problems are imminent,” the opinion from the 10th U.S. Circuit Court of Appeals said.

Cole had a lesion on his brain, which was separate from his diagnosis of paranoid schizophrenia, that had grown in size in recent years and affected the part of his brain that deals with problem solving, movement and social interaction, Conrad-Legler said.

Attorneys for the state and members of the victim’s family told the board that Cole’s symptoms of mental illness were exaggerated and that the brutal nature of his daughter’s killing merited his execution.

Assistant Attorney General Tessa Henry said Cole killed his daughter because he was infuriated that her crying from her crib interrupted his playing of a video game.

“He is not severely mentally ill,” said another prosecutor, Assistant Attorney General Ashley Willis. “There is nothing in the constitution or jurisprudence that prevents his execution.”

Prosecutors noted that the infant had numerous injuries consistent with a history of abuse and that Cole had previously served time in prison in California for abusing another child.

Board members also heard emotional testimony from family members of the slain child’s mother, who urged the board to reject clemency.

“The first time I got to see Brianna in person was lying in a casket,” said Donna Daniel, the victim’s aunt. “Do you know how horrible it is to see a 9-month-old baby in a casket?

“This baby deserves justice. Our family deserves justice.”

Oklahoma Attorney General John O’Connor said in a statement before the execution that he was confident Cole was sufficiently competent to be executed.

“Although his attorneys claim Cole is mentally ill to the point of catatonia, the fact is that Cole fully cooperated with a mental evaluation in July of this year,” O’Connor said. “The evaluator, who was not hired by Cole or the State, found Cole to be competent to be executed and that ‘Mr. Cole does not currently evidence any substantial, overt signs of mental illness, intellectual impairment, and/or neurocognitive impairment.’”