The Baltimore state medical examiner's office has found that Freddie Gray likely died from a single "high-energy injury" sustained as he rode shackled in the back of a police van on the day of his arrest, according to an autopsy report obtained by the Baltimore Sun.

The autopsy report suggested that Gray may have attempted to stand up during the van ride, and that the injury could have occurred as he was thrown against the van wall when the vehicle changed direction, according to the Sun.

The findings, which have not yet been released publicly, adds to the detailed timeline of events that occurred on April 12 as police transported Gray, 25, from the scene of his arrest to the police station. Officers reportedly did not secure Gray in a seatbelt during the ride, a violation of departmental policy, and repeatedly denied him medical assistance, investigators have revealed.

When police eventually took Gray to the hospital, doctors determined that he had sustained a severed spine and crushed voice box. His death a week later sparked rounds of intense protests that occasionally escalated into riots and looting. Six Baltimore officers now face a range of charges related to the homicide.

Prosecutors later said that police had no probable cause for Gray's arrest. Officers took Gray into custody after he reportedly fled when an officer made eye contact him. He was found with a "knife clipped to the inside of his front right pants pocket," which was later determined to be legal under Maryland law.

Investigators later determined that the van made five stops along the journey that day, some parts of which were documented on bystander cellphone and CCTV footage. The medical examiner's report relied heavily on this video, as well as witness statements and an inspection of the van. Gray had a significant injury to the lower left part of his head, likely sustained sometime between the second and fourth stops, possibly before the third, the autopsy report found.

The medical examiner reportedly said that as soon as police closed the van doors, Gray began banging against the side of the van, causing it to rock. At the second stop, Gray was reportedly "still yelling and shaking the van," the medical examiner wrote.

"He was removed from the van and placed on the ground in a kneeling position, facing the van doors, while ankle cuffs were placed, and then slid onto the floor of the van, belly down and head first, reportedly still verbally and physically active," the examiner said.

At the third stop, the van's driver reportedly got out to check on the prisoner, but did not call for backup or help until the fourth stop, when he called Sgt. Alicia White, who is one of two officers who has been charged with manslaughter in the case.

"The assisting officer opened the doors and observed Mr. Gray lying belly down on the floor with his head facing the cabin compartment, and reportedly he was asking for help, saying he couldn't breathe, couldn't get up, and needed a medic," the medical examiner wrote. "The officer assisted Mr. Gray to the bench and the van continued on its way."

During the fourth stop, another prisoner — accused of violating a protective order — was introduced into the van, separated from Gray by a metal partition. The two men reportedly could not see each other.

Before the fifth stop, the other detainee reported hearing Gray banging in the van. When officers opened the doors for the fifth time, the report noted that "Mr. Gray was found kneeling on the floor, facing the front of the van and slumped over to his right against the bench, and reportedly appeared lethargic with minimal responses to direct questions."

The examiner surmised that the other prisoner's recollection of banging before the fifth stop would not have been possible given the extent of Gray's injuries at the time, but that Gray may have been having a seizure, which created the noises.

The autopsy report did not mention any previous injuries Gray had to his spine or elsewhere, according to the Sun. The examiner added that Gray's neck injury would have had "direct effects" on his breathing ability and may have caused his limbs to stop functioning.

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