However, in a report dated 11 September, Sammarco's office concluded that the victim had been starved of oxygen as a result of "an unknown insult more than a year prior to death", the Associated Press reported.
An examination by the OH medical examiner's office said Warmbier's body appeared "well-nourished", with no physical abnormalities beyond some minor scars of indeterminate age, the Cincinnati Enquirer reports.
USA doctors has previously said there was no evidence of the botulism that North Korea had alluded to. "They're terrorists. They kidnapped Otto". "We were surprised at that statement". However, the coroner's office found a scar that "we really couldn't explain through medical instrumentation", Sammarco said.
The coroner also found a collection of scars on Otto's "well-developed, well-nourished" body.
"He was blind. He was deaf", Fred Warmbier added.
Fred Warmbier said Tuesday that his son "was jerking violently, making these inhuman sounds", when he was returned, but Sammarco said his condition was likely caused by "chronic brain damage".
The Warmbiers also expressed astonishment that North Korea was not on the State Department's roster of state sponsors of terrorism, a designation that subjects the listed countries to special financial and military sanctions. His family did not want the coroner to perform an autopsy on his body.
"We don't know what happened to him and that's the bottom line", Dr Lakshmi Sammarco said in a news conference on Wednesday.
While there is no immediate evidence of torture, there are types of abuse that might not leave physical evidence, such as scars or bone fractures.
Many on Twitter were confused about the report but felt something must have happened to cause his condition and death while in North Korea.
Sammarco said that her team discussed a potential autopsy.
Regardless of whether or not North Korea tortured Warmbier, he would nearly certainly still be alive had North Korea not detained him on wild charges.