Richard Albert Ricci shows no sign of responsiveness and has irreversible injury to the brain stem, including the portion of the brain responsible for consciousness, said Dr. Richard Sperry.
He collapsed Tuesday night in his prison cell from a spontaneous cerebral hemorrhage. Police say the question of Ricci's survival looms large in the search for Elizabeth and the investigation into her abduction.
Ricci had a history of hypertension, but was not on medication while in the prison, said prison spokesman Jack Ford.
Ricci, 48, called guards Tuesday evening and told them he had trouble breathing. They found him sitting on his bed and while they were talking to him, he passed out. They began resuscitation and he was flown to the hospital.
He was not listed as brain dead because he can still breathe on his own, Sperry said. Despite this, he is on a ventilator.
Prison officials are now facing the hard question of what to do if Ricci lives but never wakes up.
Ford said that in the event Ricci lived and his family declined to take him off life support, he still would be considered a prisoner but would have to remain at the hospital at state expense.
Doctors at the University of Utah Hospital said Rici's family now needs to make the decision whether to maintain the life support. No decision has been made yet, Sperry said.
If Ricci remained persistently vegetative, the Board of Pardons likely would release him, Ford said.
"The only thing the board's going to be considering is public safety, and if he's incapacitated, he's no further threat," Ford said.
The former handyman for the Smart family had been in prison for parole violation. Salt Lake City Police Chief Rick Dinse on Wednesday reaffirmed that Ricci remained at the top of the list of potential suspects in Elizabeth Smart's abduction.
However, investigators were no closer to finding the 14 year old than they were on June 5, when a gunman stole her from her bedroom in the middle of the night, Dinse said.
Ricci has not been charged in relation to Elizabeth's disappearance, and has maintained he had nothing to do with it.
Friday morning, Elizabeth's family turned to the public to answer questions Ricci no longer can. They said they want the answers to two questions, and are willing to pay $3,000 each for those answers.
In particular, they want to know who picked up Ricci when he left his white Jeep Cherokee at a repair shop on June 8.
Ed Smart, Elizabeth's father, says he's certain Ricci had something to do with his daughter's disappearance. He's most interested in the man who met Ricci at a car repair shop three days after the kidnapping.
"There was somebody else that knew something," Smart said.
They also asked for information regarding a July 24 attempted break-in at the Cottonwood Heights home of Jeannie and Steve Wright. Lois Smart, Elizabeth's mother, is Jeannie Wright's sister.
The families are close and regularly spent Sundays together. Elizabeth and the Wright's 15-year-old daughter also were close, Ed Smart said.
Salt Lake County sheriff's deputies reported that the screen covering the 15-year-old's window was cut and that a chair was found by the window.
The break-in also happened at the same time of night.
It may be just a coincidence, Ed Smart said. Deputies investigated the incident thoroughly, he said, but he hopes the reward would bring more information. He said initial notions that it was a prank were never verified.
A $250,000 reward was posted in June for information leading to Elizabeth's safe recovery. A separate $25,000 reward was offered for information leading to finding Elizabeth or contributing to the arrest and conviction of her abductor. Neither has been claimed.