Aaron Hernandez's brain to be returned to his family

BOSTON – Massachusetts officials on Thursday were preparing to release the brain of New England Patriots player Aaron Hernandez to his family for scientific study the day after he was found hanged in his prison cell, a death investigators formally ruled a suicide.

It remains unclear why the 27-year-old former National Football League player hanged himself early on Wednesday in the cell where he was serving a life sentence for the 2013 murder of an acquaintance. He did so less than a week after he was cleared of a separate double-murder charge.

The district attorney investigating the death said Hernandez had been alone in his cell for seven hours by the time guards found his body at 3 a.m. on Wednesday, and noted that three handwritten notes were found near a Bible in his room.

Hernandez's family wants to donate his brain to Boston University's CTE center, his attorney Jose Baez said. The center studies chronic traumatic encephalopathy, a condition linked to the sort of repeated head hits common in football that can lead to aggression and dementia.

Baez earlier on Thursday accused the state of reneging on a deal to hand Hernandez's brain over along with his body.

"The family should be able to have the dignity of a proper service in the proper possession of Aaron's remains," Baez told reporters. Baez is conducting his own investigation into the death and said he was not yet satisfied that it was clearly a suicide.

Hernandez had a $41 million NFL contract when he was arrested at his home in June 2013 and charged with murder. Prosecution witnesses at his two trials painted a picture of a troubled man with a history of drug use and paranoid tendencies.

The District Attorney for Worcester County, the site of the prison where Hernandez died, on Thursday said Hernandez's official cause of death was asphyxia by hanging.

"There were no signs of a struggle, and investigators determined that Mr. Hernandez was alone at the time of the hanging," Joseph Early said.

Baez declined to answer questions on Hernandez's mental state prior to his suicide and dismissed as "ridiculous" local media reports citing unnamed law enforcement sources that Hernandez was found with a reference to a Bible verse written on his forehead.

Hernandez was heavily tattooed and during his most recent trial jurors saw photos of two designs that depicted guns and one that read "God forgives" when viewed with a mirror.