CHARLESTON, W.Va. (AP) — Daniel J. Palmer III had long been considered the key suspect in a brutal attack that left his sister comatose two years ago. But the case remained dormant — until she awakened last month.

Able to speak only a word at a time after coming out of a coma, Wanda Palmer identified her brother — with whom she had a violent past — as her attacker. Daniel Palmer was arrested on July 15.

Less than a week later, he was dead, likely bringing a close to a highly unusual case in which the investigation was stalled by a lack of evidence.

For now, there are two mysteries: a detainee’s death, and an assault without a publicly disclosed motive.

Daniel Palmer was pronounced dead Thursday at a Charleston hospital, a day after he was taken there following an evaluation by jail medical staff, the state Department of Homeland Security, which oversees the Division of Corrections, said in a news release.

The statement didn’t indicate a cause of death and a spokeswoman for Department of Health and Human Resources, which oversees the state medical examiner’s office, said state law only allows the agency to release autopsy information to relatives and law enforcement.

Palmer, 55, of Cottageville, was uncooperative while in custody and during booking procedures at the South Central Regional Jail, where he was taken after being charged with the attempted murder and malicious wounding of his sister, the statement said.

Wanda Palmer was in a coma in a nursing home for two years. She was found unconscious with serious head injuries at her home in Jackson County on June 10, 2020.

Daniel Palmer had been identified as a suspect, but up until the time she emerged from the coma, investigators did not have enough evidence to file charges, court documents said.

“Due to a previous violent history between Wanda Palmer and her brother Daniel Palmer, investigators initially considered Daniel a suspect in the assault,” according to a criminal complaint filed in Jackson County Magistrate Court.

Investigators interviewed Daniel, who denied involvement in the attack, saying he had not been to his sister’s home in days. Later, a witness told investigators he saw Daniel in the front doorway at Wanda Palmer’s trailer on the night she was assaulted.

On June 27, more than two years after the attack, a deputy received a call from a protective services worker who said she had started to speak single words and seemed to respond when questioned.

On July 12, deputies drove to Genesis Healthcare in New Martinsville to speak with Wanda Palmer. Deputy Julia Bowen “entered Wanda’s room alone and began speaking with her,” the complaint said. “Bowen asked opened ended questions of Wanda. Wanda indicated (that) she recalled living in her trailer near her mother’s place. She indicated that she recalled being hurt there. She made mention of her head.”

Wanda Palmer said the person who injured her was her brother and she identified him as Daniel. When asked during the interview the reason behind the assault, “Wanda stated that he was mean,” according to the complaint.

Wanda Palmer ”appeared oriented to her situation. Her answers to questions were coherent and relevant. She asked for prayer.”

Daniel Palmer was being held on a $500,000 bond. He was so combative when he was arrested that it took hours to get him to cooperate with authorities for an arraignment, which required a magistrate to leave a courthouse and come to the Jackson County sheriff’s office, WCHS-TV reported.

Jackson County Sheriff Ross Mellinger was out of his office and unavailable for comment Friday.