The brain custody battle comes a day after prison officials said Hernandez, a former National Football League star for the New England Patriots, hanged himself with a bedsheet attached to a window in his prison cell.
It was Jose Baez - the family attorney - who first revealed the family's intentions to donate the brain to help advance with the study of CTE.
"We had made arrangements for Boston University to come at 10 a.m.to pick up Aaron's brain", Baez said, but he added that the medical examiner's office had decided "at the last minute" to hold it longer.
The District Attorney investigating the death said Hernandez's brain would be released to his family now that an investigation of the body by the Office of the Chief Medical Examiner had been completed.
Baez said officials from the chief medical examiner's office told him they wanted to prepare the brain for study.
"It is our position that they are holding Aaron Hernandez's brain illegally", Baez said during a news conference.
Retailer BeBe to Close All Stores
Bankruptcy filings of other retailers within the last several weeks have included Payless ShoeSource, Gander Mountain and HHGregg. In March, Bebe management and its board said they would explore "strategic alternatives" and hired financial advisor B.
Corrections department spokesman Christopher Fallon said no suicide note was found during an initial search of Hernandez's cell.
Law enforcement sources told ABC News that Hernandez was found with the Bible verse John 3:16 written across his forehead in red marker. He was serving a life sentence for the 2013 shooting death of a onetime friend, though his legal team had plans to appeal the conviction.
Aaron Hernandez's top lawyer says he has retained prominent medical examiner Dr. Michael Baden to conduct an independent autopsy.
Aaron Hernandez's death in prison has been officially ruled a suicide.
During his trial in Boston for the killing of two men in Boston in 2012, Hernandez appeared upbeat, constantly backslapping his lawyers, letting out bellowing laughs and blowing kisses to his 4-year-old daughter and other family members in the audience.
He issued a statement Wednesday saying that Hernandez's family and legal team are "shocked and surprised" at the news of his death.
Russian Federation vetoes United Nations draft resolution on Syria
There are legitimate questions, posed by the Russians and others, as to who would take power after Assad's departure. The latest attack, which killed more than 85 civilians and injured over 550, was part of this ongoing campaign.
White also said while the trial may have related to his death, it likely wasn't the only cause.
In Dorchester, the Boston neighborhood where Lloyd grew up, a family friend of the Lloyds wondered if the weight of Hernandez's crimes - and of great potential squandered - had finally caught up with him.
But the Patriots released him in 2013, shortly after he was arrested in the killing of semi-pro football player Odin Lloyd, who was dating the sister of Hernandez's fiancee.
He signed a 5 year, $40 million deal with the Patriots in 2010, but hung out with a risky crowd.
The former New England Patriots tight end was pronounced dead at UMass Memorial-HealthAlliance Hospital in Leominster about an hour later.
That information comes from a joint statement from Worcester County District Attorney Joseph Early Jr., Massachusetts State Police Superintendent Col. Richard McKeon, and Secretary of Public Safety Daniel Bennett.
Trump signs executive order for overhaul of H-1B visa system
This means the visas should not be granted to foreign workers who are simply willing to work for less than US workers. These companies connect USA technology firms with thousands of foreign engineers and programmers.