Otto Warmbier's death and the events in North Korea that led up to it remain a mystery.

North Korean officials said that during his 17 months in detention for “hostile acts against the state,” Warmbier had contracted botulism, was given a sleeping pill and never woke up.

Last week, after nearly a year and a half in captivity, the 22-year-old University of Virginia student was brought home to Ohio in a coma. Doctors there said he had extensive loss of brain tissue  and had suffered a severe neurological injury. Warmbier died Monday, six days after being flown back to the United States.

But what led to Warmbier's death? And will an autopsy be able to provide any answers?

Experts say postmortem examinations can be illuminating, but the amount of time that has passed since Warmbier fell into a coma may limit what pathologists would be able to find.

“The most important thing I think it could tell us is the general nature of what caused the brain damage and it might give us some idea if it was continuing or in the past,” said Victor Weedn, a forensic pathologist and professor of forensic sciences at George Washington University. But, he said, “it may or may not be able to tell the underlying cause of the damage.”

Weedn said an autopsy may also help to rule out causes, including trauma or infection. In some cases, he said, autopsies can help find discrepancies in stories.

“If he was roughly treated, we may be able to see signs of that,” he said. “If they tortured him in some way, there may be signs of that — but there could also not be signs of that.”

Still, several pathologists have said that after months and months, signs can fade away.

Werner Spitz, a forensic pathologist who has worked on numerous high-profile cause-of-death investigations, said that he is not particularly hopeful that Warmbier’s autopsy will be able to shed much light on what happened to him, given how long his body has had to erase the evidence.

“After a year of this fellow being unconscious, it is a futile effort,” said Spitz, who worked as a medical examiner in Baltimore and Detroit and is now a professor of pathology at Wayne State University School of Medicine. He said, “there are a lot of things that will not show any longer.”

Bruises, cuts and other markings on the skin would be among the first to fade, likely leaving behind no trace that they were ever there. Damage to bones or organs might show scars, but it would be difficult to determine how long ago they occurred. If Warmbier had been mishandled by North Korean security officials in such a way that it affected his ability to breathe, Spitz said, “it will not show at all.”

All that may be clear at the time of autopsy, pathologists say, is the resulting brain damage.

One exam that may provide a hint of what happened will give a closer look at the brain.

“Certain areas of the brain are more susceptible to oxygen deprivation than others. When those areas are affected, that tells you a lot about what happened in the past,” said Spitz, whose past cases included the deaths of President Kennedy and Nicole Brown Simpson. “And since he was conscious and well when he went there, and shortly he became unconscious, that all adds up together not necessarily in their favor over there.”

A complete autopsy with a neuropathology examination could reveal numerous causes for brain injury, such as anoxia, insufficient oxygen to the brain; or deprivation caused by intoxication, smothering or strangulation, or physical trauma, said Brian Peterson, president of the National Association of Medical Examiners. “Bottom line — months later — there would be nothing particular to find at autopsy except for the damaged brain,” Peterson told The Washington Post in an email.

Weedn, the forensic pathologist at George Washington University, said he suspects that the pathologist who examines Warmbier's brain will most likely see there was a lack of oxygen.

“With somebody who has been comatose and then died, I would expect to see brain damage and I would expect to be able to better describe it” but not necessarily explain it, Weedn said.

At the very least, Weedn said, autopsies can provide closure for families and their communities.

“When you don’t do that, then families often linger with nagging questions that may have been resolved at autopsy,” he said, adding that examinations in this case could also be important for international affairs. “An autopsy is the way that you are best able to get good evidence. That is, it matters.”

This post has been updated.

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