NY1 has obtained a never-before-seen look at Joshua Valles' final moments on Rikers Island.

Valles died after spending less than six weeks on Rikers Island in the spring of 2023 for burglary. His death at the time sparking controversy and outrage.

And now, exclusive video obtained by NY1 from the Department of Correction through the Freedom of Information Law shows what happened just before Valles was taken to the hospital where he was pronounced brain dead.

His death is still perplexing his attorney and his family.

"I think there is a lot of questions around his death and a lot of deaths that have occurred on Rikers Island," Stan Germán of the New York County Defender Services, who represented Valles, said.

The Department of Correction did not answer NY1's questions for this story. A spokesperson only said Valles's death is under investigation.

Valles' death first came to light in reporting from the court-appointed Rikers federal monitor — the subject of a damaging special report from the monitor in May of 2023.

The monitor slammed the department for initially failing to even notify them that Valles was on life support in the hospital, and it questioned the department's rationale that there had been no wrongdoing.

Days later, the monitor reported an autopsy revealed Valles died as a result of a fractured skull.

But the record since has become more complicated.

In July, the city’s medical examiner found Valles' cause of death was natural — caused by an unknown, non-traumatic seizure disorder.

The city’s Department of Investigation inquiry has closed. The state attorney general is still investigating.

Video NY1 obtained shows a brief fight Valles got into with another detainee shortly after arriving on Rikers in April.

It also shows Valles on the day he is sent to the hospital, complaining of a headache.

During that transfer, he had a seizure in the ambulance and, according to his attorney, then went into cardiac arrest and was resuscitated at the hospital. He had significant brain swelling, the attorney said. The following day he was found to be brain dead.

Before that, Valles appears to be in his cell alone. Video reviewed by NY1 shows a medical official checking on him. An officer came over as well, and he was taken to the clinic later on.

The video obtained by NY1 from the Department of Correction does not show any head trauma occurring to Valles that day. But NY1 was only given a tiny sliver of video of his time in custody.

Medical experts who reviewed the records and video obtained by NY1 have said it's inconclusive. NY1 was not able to obtain the full medical examiner's report.

"Whether or not you have a seizure or blunt force trauma, the inmate walking and complaining about a headache, both could be the cause of the headache,” Angelique Corthals, an associate professor at John Jay College of Criminal Justice, said. “Obviously if you have a fractured skull you will complain of a headache. But a headache is also very common following a severe seizure."

There are lingering questions about his time and treatment in those final days and hours.

Since Valles's death, a former social worker, Justyna Rzewinski, with the city's health care provider on Rikers, has called out the department for repeatedly locking in detainees in mental health units in their cells — failing to get them medication.

"I witnessed a widespread practice known as deadlocking, where patients are locked in their cells for weeks and weeks without access to medications,” Rzewinski told the Board of Correction in October. “These individuals began to decompensate rapidly."

It's unclear if that is what happened to Valles. But the testimony is raising questions about how he was treated in his final days.

"Just the act of locking a seriously mentally ill person in his cell in it of itself is illegal,” Germán told NY1.

According to the Board of Correction, Valles was diagnosed with schizoaffective disorder and had a history of psychiatric hospitalizations. He was housed in a mental health unit on Rikers.

A Board of Correction report examining Valles' death from last year states Valles was locked in his cell on his mental health unit but it's unclear for how long.

The report states he was locked in because he was exhibiting “childlike behavior.”

Valles allegedly expressed his frustration by banging on the door of his cell. But the report could not determine whether he used his head or just his fist.

Te same report questions whether officers were appropriately checking in on Valles often enough.

"So simply these benign behavioral attributes and the way he was exhibiting was enough for somebody from the DOC, not the medical side, the DOC side, to deadlock Mr. Valles,” Germán said. “Unfortunately, from the video we don't know how long the deadlock took place. We don't know whether he was checked on when he was deadlocked. We don't know in the throes of trying to get attention he hit his head while he was going through this time of mental instability."

The Valles family is suing the city for negligence and wrongful death. They are asking for $100 million.